Quick Recipe Version (TL;DR)

Yield: 4 servings
Prep Time: 20 minutes
Cook Time: 25 minutes
Total Time: 45 minutes

Quick Ingredients

1 lb (450 g) Brussels sprouts, trimmed and halved
12 oz (340 g) short pasta (fusilli, rigatoni, or orecchiette)
3/4 cup (75 g) walnuts, divided
1 cup packed fresh parsley leaves
1/2 cup fresh basil leaves (or more parsley)
1 large lemon (zest + 2 tbsp juice)
3 cloves garlic
1/2 cup (50 g) finely grated Parmesan cheese
1/3–1/2 cup (80–120 ml) extra-virgin olive oil, plus more for roasting
Salt, black pepper, and crushed red pepper flakes (optional)

Do This

1. Heat oven to 425°F (220°C). Toss halved Brussels sprouts with 2 tbsp olive oil, salt, pepper, and a pinch of red pepper flakes. Roast on a sheet pan, cut side down, for 15–20 minutes until browned and tender.
2. In the last 5–7 minutes of roasting, scatter walnuts on one side of the pan and toast until fragrant and lightly golden. Cool slightly, then roughly chop.
3. Meanwhile, cook pasta in a large pot of well-salted boiling water until al dente. Reserve 1–1 1/2 cups pasta cooking water, then drain.
4. Make pesto: In a food processor, blend herbs, 1/2 cup toasted walnuts, garlic, lemon zest, 2 tbsp lemon juice, Parmesan, salt, and pepper. With the motor running, stream in 1/3–1/2 cup olive oil until you get a bright green, spoonable sauce.
5. Return drained pasta to the warm pot. Add pesto and a splash of reserved pasta water. Toss over low heat until glossy and well coated, adding more pasta water as needed.
6. Fold in most of the roasted Brussels sprouts and some of the remaining walnuts. Taste and adjust with extra lemon, salt, or pepper.
7. Serve topped with remaining sprouts, walnuts, extra Parmesan, and a drizzle of olive oil.

Why You’ll Love This Recipe

It turns humble Brussels sprouts into crispy, caramelized, irresistible bites.
The bright green walnut-herb pesto is packed with flavor but easy to make in a food processor.
Lemon zest and garlic keep the pasta fresh and lively, never heavy.
It is weeknight-friendly yet impressive enough for guests.

Grocery List

Produce: Brussels sprouts, fresh parsley, fresh basil (or extra parsley), 1 large lemon, garlic
Dairy: Parmesan cheese (or vegetarian/vegan hard cheese substitute, if desired)
Pantry: Short pasta, walnuts, extra-virgin olive oil, salt, black pepper, crushed red pepper flakes (optional)

Full Ingredients

Pasta and Roasted Brussels Sprouts

1 lb (450 g) Brussels sprouts, trimmed and halved (or quartered if very large)
2 tbsp extra-virgin olive oil
1/2 tsp kosher salt (plus more to taste)
1/4 tsp freshly ground black pepper
1/4 tsp crushed red pepper flakes (optional, for mild heat)
12 oz (340 g) short pasta (fusilli, rotini, rigatoni, or orecchiette)
Salt for the pasta water (about 1 1/2 tbsp kosher salt for a large pot)

Herby Walnut Pesto

3/4 cup (75 g) walnuts, divided
1 cup packed fresh parsley leaves
1/2 cup fresh basil leaves (or substitute more parsley for a parsley-only pesto)
2–3 cloves garlic, roughly chopped
1 tsp finely grated lemon zest (from about 1 large lemon)
2 tbsp freshly squeezed lemon juice
1/2 cup (50 g) finely grated Parmesan cheese
1/2 tsp kosher salt, plus more to taste
1/4 tsp freshly ground black pepper
1/3–1/2 cup (80–120 ml) extra-virgin olive oil (start with 1/3 cup and add more as needed)
2–4 tbsp reserved hot pasta cooking water, as needed to thin the sauce

For Serving

Extra finely grated Parmesan cheese
Extra lemon zest or a squeeze of lemon juice
Drizzle of extra-virgin olive oil
Extra black pepper and/or crushed red pepper flakes
A few extra parsley or basil leaves, for garnish (optional)

Step-by-Step Instructions

Step 1: Prep the oven and Brussels sprouts

Preheat your oven to 425°F (220°C). Line a large rimmed baking sheet with parchment paper for easier cleanup, if you like.

Trim the stem ends from the Brussels sprouts and remove any wilted outer leaves. Cut each sprout in half from top to bottom (or into quarters if they are very large) so they roast evenly and get lots of surface area to caramelize.

Place the Brussels sprouts on the baking sheet. Drizzle with 2 tbsp olive oil, then sprinkle with 1/2 tsp kosher salt, 1/4 tsp black pepper, and 1/4 tsp crushed red pepper flakes if using. Toss directly on the sheet until everything is well coated, then spread the sprouts out in a single layer, cut side down. Leaving them cut-side-down helps them develop a deep golden crust.

Step 2: Roast the Brussels sprouts and toast the walnuts

Slide the tray into the hot oven and roast for 10 minutes. While they roast, roughly measure out 3/4 cup walnuts and keep them handy.

After 10 minutes, remove the tray, give the sprouts a quick toss with a spatula, and push them slightly to one side to make room for the walnuts. Scatter the walnuts in a single layer on the empty area of the pan.

Return the tray to the oven and roast for another 5–7 minutes, until the Brussels sprouts are nicely browned with some charred edges and the walnuts are fragrant and lightly toasted. Watch closely in the last couple of minutes so the walnuts do not burn.

Remove from the oven. Let everything cool on the tray for a few minutes. Transfer the walnuts to a cutting board and roughly chop. Set aside. Leave the Brussels sprouts on the tray for now.

Step 3: Cook the pasta and reserve some cooking water

While the Brussels sprouts roast, bring a large pot of water to a boil. Salt it generously (about 1 1/2 tbsp kosher salt for a large pot; it should taste pleasantly salty like the sea).

Add 12 oz of pasta and cook according to package directions until just al dente, usually 8–11 minutes depending on the shape. Stir occasionally so it does not stick.

Before draining, scoop out 1–1 1/2 cups of the hot, starchy pasta water and set it aside in a heatproof measuring cup or bowl. This will be used to thin and emulsify the walnut pesto so it clings to the pasta.

Drain the pasta, then return it to the warm pot off the heat. Toss the pasta with a small splash of olive oil or a spoonful of the reserved pasta water to keep it from sticking while you make the pesto.

Step 4: Make the bright green herby walnut pesto

In a food processor bowl, combine the fresh parsley, fresh basil (or extra parsley), chopped garlic, lemon zest, lemon juice, Parmesan cheese, 1/2 tsp kosher salt, 1/4 tsp black pepper, and about 1/2 cup of the toasted walnuts (reserve the rest for topping).

Pulse several times until everything is finely chopped but not yet a paste. Scrape down the sides of the bowl as needed so no large chunks remain.

With the processor running, slowly stream in 1/3 cup olive oil. Stop and check the consistency. You are aiming for a thick but spoonable, bright green sauce. If it looks too thick or dry, add up to another 2–3 tbsp olive oil and pulse again.

For an extra silky, clingy sauce, add 2–4 tbsp of the hot reserved pasta cooking water and pulse briefly until just combined. Taste and adjust: add a pinch more salt, another squeeze of lemon, or a bit more black pepper as needed. The pesto should taste bright, nutty, and well seasoned on its own.

Step 5: Toss the pasta with pesto and lemon

Place the warm drained pasta back over very low heat (or simply keep it off the heat if your pot retains heat well). Spoon the walnut-herb pesto over the pasta.

Add about 1/2 cup of the reserved pasta water to the pot. Toss vigorously with tongs or a large spoon, coating every piece of pasta. The sauce should start to loosen and become glossy, clinging to the pasta rather than pooling at the bottom. If it looks too thick or dry, add more pasta water a splash at a time until it looks silky and well distributed.

Grate in a little extra lemon zest if you love a more pronounced lemon flavor, and stir to combine.

Step 6: Fold in the roasted Brussels sprouts and walnuts

Gently add most of the roasted Brussels sprouts to the pasta pot, reserving a small handful for topping each plate. Add about half of the remaining chopped toasted walnuts as well.

Toss gently so you do not break up the sprouts too much. You want some pieces to mix into the sauce and some to stay chunky for texture. Taste the pasta and adjust the seasoning: add more salt, black pepper, or lemon juice if it tastes flat, or a pinch of crushed red pepper if you want a little heat.

Step 7: Serve and garnish

Divide the pasta among warm bowls or plates. Top each portion with the reserved roasted Brussels sprouts and a sprinkle of the remaining chopped walnuts.

Finish with a generous shower of finely grated Parmesan, a drizzle of extra-virgin olive oil, and an extra sprinkle of lemon zest, black pepper, and/or red pepper flakes to taste. Garnish with a few fresh parsley or basil leaves if you like, and serve right away while everything is hot and fragrant.

Pro Tips

Cut side down for maximum caramelization: Arrange Brussels sprouts cut-side-down on the tray so they get deep golden, crispy edges instead of steaming.
Watch the walnuts closely: Walnuts can go from perfectly toasted to bitter in a minute. Check them a bit early and pull the tray if they smell very nutty and look golden.
Salt the pasta water generously: This is your main chance to season the pasta itself. Properly salted water makes the whole dish taste better.
Use the pasta water as a tool: Starchy pasta water is what transforms the pesto into a glossy sauce that clings. Add it gradually until the pasta looks lightly sauced, not soupy.
Adjust lemon and garlic to taste: If you love bright, punchy flavors, add an extra clove of garlic or a bit more lemon juice right at the end.

Variations

Make it vegetarian-friendly or vegan: Use a vegetarian hard cheese made without animal rennet, or swap the Parmesan for 3–4 tbsp nutritional yeast to keep it fully vegan. Check that your pasta is egg-free if needed.
Add protein: For a heartier meal, top each bowl with grilled chicken, roasted shrimp, or crispy chickpeas. All work beautifully with the lemony, herby sauce.
Different herbs and nuts: Swap some or all of the parsley for baby spinach or arugula, or trade walnuts for toasted almonds or hazelnuts for a different twist on the pesto.

Storage & Make-Ahead

The walnut-herb pesto can be made up to 3 days ahead. Store it in an airtight container in the refrigerator with a thin layer of olive oil on top to keep the herbs bright. Give it a stir and loosen with a splash of warm water or pasta water before using.

Roasted Brussels sprouts can be cooked a day in advance and chilled in an airtight container; reheat them briefly in a hot oven or skillet to revive their texture before adding to the pasta.

Leftover assembled pasta will keep in the refrigerator for up to 3 days. Store in an airtight container. Reheat gently on the stovetop over low heat with a splash of water or broth to loosen the sauce, or microwave in short bursts, stirring in between. The pasta will soften slightly but will still be delicious.

Nutrition (per serving)

Approximately per serving (1/4 of the recipe): about 780–820 calories; 70–80 g carbohydrates; 40–45 g fat; 20–25 g protein; 6–9 g fiber; 4–6 g saturated fat; 650–800 mg sodium (varies with salt and cheese); and a good amount of vitamin C, vitamin K, and heart-healthy fats from the olive oil and walnuts. These values are estimates and will vary based on the exact ingredients and brands used.

Lemony Brussels Sprout Pasta With Walnut Herb Pesto