These sandwiches are wonderful as is, though you can certainly layer on some sliced turkey or sharp Cheddar if you like. Pick up the best ingredients—a juicy heirloom tomato, fresh lettuce, and good-quality bacon—to ensure the best flavor in this classic sandwich.
In a small bowl, mash one of the avocados with the lemon juice and 1/4 tsp. salt. Taste and season the avocado with more lemon juice and salt if needed. Slice the second avocado into thin slices. Fan the tomato slices on a large plate, drizzle with 1 Tbs. oil, and sprinkle with 1/2 tsp. salt.
In a large (12-inch), heavy-duty skillet (like cast-iron), cook the bacon with the remaining 1 Tbs. oil over medium heat, flipping occasionally, until it browns and renders much of its fat, about 5 minutes. Transfer the bacon to a plate lined with paper towels. Add the onion rounds to the skillet, sprinkle lightly with salt, and cook until they start to brown, about 2 minutes.
Flip and cook until the other sides brown but they are still firm, about 2 more minutes. Remove from the heat.
For each sandwich, spread the mashed avocado on one bread slice. Top with 2 slices of tomato, 2 onion rounds, bacon, lettuce, and avocado slices. Add the remaining slice of bread, and serve.
Serve with Grilled Yellow Tomato Bisque.
Photo: Maren Caruso