My Special Spanish Tortilhas

Hi everyone.
I love egg tortilha, a Spanish traditional dish but very common in Portugal. I do different types of tortilhas because I change the ingredients. After prawn tortilha, the one in the picture is my favorite type.

Ingredients:

~ 4 eggs
~ 2 tablespoons of milk
~ 1/2 small onion
~ Homemade chips
~ Cheese - any type
~ 5/8 slices of sweet pepper, both green and red
~ 1/2 teaspoon of vegetable butter
~ Fresh parsley and salt

Directions:

I like doing omelettes and tortilhas in anti-adherent pan to avoid sticking and because I don´t have to use much butter.
Slice the onion into the pan, add the butter and let it fry (2/3 minutes). Add the chips in a way they cover all pan bottom. Reserve while you prepare the eggs.
In a bowl mix the eggs, milk, fresh parsley and a pinch of salt. Put the pan back in the stove in low temperature. The low temperature is important because egg tortilhas burn easily.
Add the eggs, cheese, and slices of sweet pepper. In another version instead of peppers I use mushrooms.
Let the tortilha fry for some minutes. You can roll it like I did, or just fry in both sides using a plate to help turning the tortilha.
I serve tortilhas with lettuce and carrot salad but it also goes well with rice, chips or any vegetables.
Bom Apetite!