01 - Preheat oven to 375°F. Lightly grease a baking dish large enough to accommodate all pepper halves in a single layer.
02 - Arrange bell pepper halves cut side up in the prepared dish. Drizzle with olive oil and season lightly with a pinch of kosher salt and black pepper.
03 - In a large mixing bowl, combine the ricotta, Parmesan, mozzarella, egg, chopped basil, parsley, chives, minced garlic, lemon zest, 1/2 tsp kosher salt, and 1/4 tsp black pepper. Stir until the mixture is smooth and uniformly blended.
04 - Spoon the ricotta filling evenly among the pepper halves, distributing it generously. Smooth the surface of each filled pepper with the back of a spoon.
05 - Cover the baking dish tightly with aluminum foil and bake for 25 minutes to allow the peppers to soften and the filling to begin setting.
06 - Remove the foil and continue baking for 10 minutes, or until the filling is fully set and the tops develop a light golden color.
07 - Remove from the oven and let the peppers rest for a few minutes. Garnish with additional fresh herbs if desired and serve warm.