BELT Sandwich with Lemony Mayo on Sourdough

Why You’ll Love This Recipe

• Balanced textures: shatteringly crisp bacon, juicy tomato, crunchy lettuce, and a silky, runny yolk.
• Bright lemony mayo lifts the rich ingredients and pairs perfectly with black pepper.
• Fast and doable on a busy morning or lazy weekend—done in about 20 minutes.
• Uses simple pantry staples with just one pan and minimal cleanup.

Grocery List

• Produce: 1 lemon, 1 large ripe tomato, 1 head romaine or green leaf lettuce
• Dairy: 2 large eggs, unsalted butter (small amount)
• Pantry: Thick-cut bacon, sourdough bread, mayonnaise, fine salt, flaky sea salt, freshly ground black pepper

Full Ingredients

Lemony Mayo

• 2 tbsp mayonnaise
• 1 tsp finely grated lemon zest
• 2 tsp fresh lemon juice
• 1/8 tsp fine sea salt
• 1/4 tsp freshly ground black pepper

Sandwiches

• 6 slices thick-cut bacon
• 4 slices sourdough bread (1/2-inch thick)
• 2 large eggs
• 4 large crisp lettuce leaves (romaine or green leaf), dried well
• 8 thin slices ripe tomato (from 1 large tomato)
• 2 tsp unsalted butter or neutral oil (for frying eggs)
• Pinch flaky sea salt, to finish
• 1/4 tsp freshly ground black pepper, to finish (or to taste)

Step-by-Step Instructions

Step 1: Mix the lemony mayo

In a small bowl, whisk together the mayonnaise, lemon zest, lemon juice, 1/8 teaspoon fine sea salt, and 1/4 teaspoon freshly ground black pepper. Taste and adjust lemon or salt as desired. Set aside.

Step 2: Cook the bacon until crisp

Place the bacon in a large, cold skillet in a single layer. Turn the heat to medium and cook, flipping occasionally, until deeply browned and crisp, 8–10 minutes. Transfer to a paper towel–lined plate to drain. Pour off and reserve a teaspoon or two of the bacon fat if you plan to toast the bread in the pan.

Step 3: Prep the veggies

Slice the tomato into thin, even rounds. Sprinkle with a small pinch of salt and let sit 2 minutes; blot excess moisture with a paper towel. Rinse and dry the lettuce thoroughly so the sandwich stays crisp.

Step 4: Toast the sourdough

Toast the sourdough slices until golden and crisp. For maximum flavor, wipe the skillet and toast the bread in a thin film of bacon fat over medium heat for 1–2 minutes per side. Alternatively, use a toaster. Keep the toast warm.

Step 5: Fry the eggs with runny yolks

Heat 2 teaspoons butter (or reserved bacon fat) in the skillet over medium heat. Crack in the eggs and cook until the whites are mostly set, 2–2 1/2 minutes. Cover the pan for 30–45 seconds to finish setting the whites while keeping the yolks runny. Season lightly with a pinch of salt and a few grinds of black pepper.

Step 6: Assemble the B.E.L.T.

Spread lemony mayo over one side of each toast slice. On two slices, layer in order: lettuce (to create a moisture barrier), bacon, tomato, and a generous shower of black pepper. Top with a runny fried egg, then cap with the remaining toast slices. Press gently, slice in half, sprinkle with flaky sea salt and more pepper if you like, and serve immediately.

Pro Tips

• Build smart: Lettuce under the tomato keeps the toast from getting soggy.
• Season tomatoes early: A light sprinkle of salt draws out excess moisture for cleaner layers.
• Bacon 101: Starting bacon in a cold pan renders fat evenly and prevents scorching.
• Runny yolk made easy: Cover the pan briefly to set the whites without overcooking the yolks.
• Alternative bacon method: Bake at 400°F (205°C) on a rack-lined sheet until crisp, 15–20 minutes.

Variations

• Avocado B.E.L.T.: Add 1/4 sliced avocado per sandwich and a pinch of flaky salt.
• Spicy lemon-pepper mayo: Stir in 1/2–1 tsp hot sauce or 1/4 tsp crushed red pepper.
• Cheesy melt: Lay a slice of sharp cheddar on the toast during Step 4 to warm and soften.

Storage & Make-Ahead

The assembled sandwich is best eaten immediately. The lemony mayo can be made up to 4 days ahead and refrigerated in an airtight container. Bacon can be cooked 2 days ahead; cool, refrigerate, and re-crisp in a 375°F (190°C) oven for 3–4 minutes. Slice tomatoes and wash lettuce just before assembling for best texture. Toast and eggs should be cooked right before serving.

Nutrition (per serving)

Approximate per sandwich: 520 calories; 32 g fat; 35 g carbohydrates; 3 g fiber; 6 g sugar; 22 g protein; 1,000 mg sodium.