Penne with 3 different onions and feta&parmesan cheese mixture

I am a big fan of "Orangette" and a few other food blogs. And sometimes, like yesterday, I get inspiration from them as to what to make that is not boring but not too complicated either. I wish I could dedicate many many hours to cooking, but I don't have that much time at the moment. Wondering what to cook to accompany the chocolate puddings (these were a sure deal) I came across a pasta recipe from Orangette called "Rigatoni with five Lilies and Ricotta salata". It sounded fancy. When I got to read it though, I discovered it was a pasta with different kinds of onions and herbs, basically whatever you have from your garden. Very simple. My recipe is an adaptation of it, which, in turn, is an adaptation from a recipe taken from the Babbo Cookbook and the San Francisco Chronicle.
I decided to use a mixture of feta and some parmesan cheese for topping instead of Ricotta salata (the salty and hard version of Ricotta) and found it delicious but maybe that's just because this taste is so rooted in me. I also skipped the scallions as there weren't any at the supermarket and used the penne that I had in my pantry instead of the rigatoni pasta.

Ingredients:

3 tbs olive oil (always extra virgin, the best you can find)
1/2 kg sweet onions cut in half from the stem and then cut to slices
2 tbs unsalted butter
5 medium garlic cloves, minced
1/2 kg leeks, cut into rings and washed
1 big red onion, quartered and sliced
1/2 cup of water
salt and pepper to taste
1/2 kg penne
feta and parmesan cheese to top
1 bunch of finely chopped fresh parsley to top


1. In a large skillet, warm the olive oil over medium heat and add the sweet onions. Reduce the heat and cook over medium-low until softened and translucent. Then raise the heat to medium-high and cook until deeply golden and caramelised. Remove the pan from the heat and transfer the onions to a bowl. Set aside.

2. In the same skillet, heat the butter over medium heat. When it has stopped foaming and is thoroughly melted, add the leeks, garlic and red onion and cook until really soft and golden. Add the water and cook until the liquid evaporates. Season to taste with salt and pepper, remove from the heat and stir in the caramelised onions.

3. Bring a large pot of salted water to a boil and add the pasta. Cook until tender but al dente.
Drain the pasta and add to the onion mixture, toss for 1 minute over medium heat and serve immediately, topped with plenty of feta and parmesan cheese and sprinklings of parsley.