4 Tbsp olive oil
2 garlic cloves, minced
4 scallions, white and green parts finely chopped
1 medium green bell pepper, seeded and finely diced
1 medium red bell pepper, seeded and finely diced
5 large eggs
1/2 cup sour cream
6 oz Parmigiano-Reggiano or Spanish Rocal cheese, grated
3 Tbsp snipped fresh chives
Kosher salt and fresh black pepper, to taste
Preheat oven to 375°F.
Place the 4 Tbsp olive oil, garlic, scallions and bell peppers in a frying pan and cook over medium heat, stirring, for 5-6 minutes, or until the onions are softened but not browned. Let cool a bit, then stir in the cooked potato.
In a large bowl, beat the eggs, sour cream, cheese and chives together. Stir in the vegetable-potato mixture, and season to taste with salt and pepper.
Pour the mixture into the baking dish and smooth the top. Bake for 40 minutes, or until golden brown, puffed, and set in the center. Remove from the oven and let cool and set. Run a spatula around the edge, then invert onto a cutting board, browned-side up. If the surface looks a little runny, place it under the broiler to dry out.
Let cool completely. Neaten the edges if necessary, then cut into one-inch squares. Serve on a platter with wooden toothpicks.