Cook the spaghetti according to the package instructions until it's al dente. Drain and set aside.
In a large bowl, beat the eggs and add the grated Parmesan cheese.
In a non-stick frying pan, heat the olive oil and sauté the garlic until it's fragrant.
Add the cooked spaghetti to the pan and toss it with the garlic.
Pour the egg and cheese mixture over the spaghetti, ensuring that it's evenly distributed.
Cook on medium heat until the bottom is golden and the top is set, about 10 minutes. You can cover the pan to help the top set faster.
Carefully flip the frittata and cook the other side for about 5 minutes.
Remove from the heat and let it cool before cutting into it.
Notes
Make sure to cook the spaghetti until it is just al dente. This will prevent it from getting too soft when it's cooked again in the frittata.
Beat the eggs well to ensure that they distribute evenly throughout the spaghetti and create a cohesive dish.
Use a non-stick frying pan to avoid the frittata sticking and to make flipping it easier.
Feel free to add other ingredients to your frittata like cooked vegetables or meat. Just make sure they are fully cooked before adding them to the mixture.
Allow the frittata to cool for a few minutes before cutting into it to maintain its shape.