Preheat the oven to 400°F. Line a baking sheet with parchment paper and arrange the bacon in a single layer. Bake until crispy, about 15–20 minutes depending on thickness.

While the bacon cooks, rinse and prep your produce. Chop the butter lettuce, slice the heirloom tomatoes, and thinly slice the green onions.

Toast your bread just before the bacon finishes cooking.

To assemble, spread mayo on your toasted bread, then layer on the lettuce, tomatoes, and bacon. Finish with a drizzle of olive oil, some green onions, some flaky salt, and lots of freshly cracked black pepper.