I often sauté fresh vegetables to my torta depending on what I have on hand in the pantry, refrigerator, and summer garden. If you choose to add fresh or frozen vegetables to the torta, simply sauté them after you have cooked the onions and before you add the garlic to the skillet and proceed as directed in the recipe.
Heat a 9 inch cast iron skillet over medium heat. Add the oil, allowing it to completely coat the bottom surface of the pan. Add the onion and sauté until translucent, taking care not to burn, approximately five minutes. Add the garlic and stir to combine, sautéing for 1-2 minutes until the garlic is fragrant but not browned. Remove the skillet from the heat and allow the mixture to cool a bit.
In a large bowl, combine the ricotta, mozzarella, and eggs. Add a bit of salt and pepper and stir to combine. Add the onion mixture and the leftover pasta, stirring to combine. Transfer the mixture back to the cast iron skillet, top with the Parmesan cheese, and transfer to the preheated oven.
Bake for 30-40 minutes until the torta is firm and lightly browned on top. When it is done, the torta should pull away from the sides of the pan slightly. Remove the skillet from the oven, allow the torta to cool and set up for about five minutes. Cut into wedges and serve with bread and a crisp salad, drizzling with a bit of balsamic glaze if desired.
Notes
Much like a quiche, this torta is equally delicious served as leftovers at room temperature the next day.