5 strips bacon
1 medium onion, finely chopped
Kosher salt
3 eggs
1 cup ricotta cheese
1/2 cup grated Parmesan cheese
Freshly ground pepper
8 ounce cooked spaghetti
1 cup frozen peas
Lemon wedges, for serving
Preheat oven to 375 degrees. Meanwhile, cook bacon in a skillet over medium heat, flipping once, until crisp, about eight minutes. Transfer bacon to paper towels to drain; reserve skillet. Let bacon cool completely, then finely chop.
Heat bacon drippings in the reserved skillet over medium-high heat. Add the onion and 1/4 teaspoon salt and cook, stirring, until soft, about five minutes. Transfer onions to a large bowl and let cool slightly. Add the chopped bacon, eggs, ricotta, Parmesan, and 1/2 tsp each salt and pepper and stir to combine. Stir in the spaghetti and peas until evenly coated.
Transfer spaghetti-egg mixture to a nine-inch pie plate or other round baking dish. Bake until the top is golden and the filling sets; 30 to 35 minutes. Transfer to a wire rack and let cool slightly. Serve with lemon wedges for squeezing over the pie.