Spinach and Onion Pasta

Like all my favourite recipes, this one has evolved. While spinach and onions have been the only constant ingredients, often it's the other ingredients that I add that really give it the flavour. I've been making it in California in somewhat Mediterranean style:

Ingredients:
Half an onion*
Half a red pepper
Frozen spinach
Oregano
Black olives
Feta cheese or pine nuts
Olive oil
Pasta of some sort (I normally use spirals)

Instructions:
Bring a saucepan of water to the boil and add the pasta. While the pasta is cooking, chop onion into small pieces. Put olive oil in a frying pan, and add the chopped onion and oregano. Slice the red pepper and add to frying pan, then add the frozen spinach. If using pine nuts, add these when the spinach is no longer frozen. You can chop the olives and add them to the frying pan, or just put them on the top when you're done (I tend to alternate depending on whether I want their flavour to be separate or blended with the rest).

When everything is cooked, put spinach mixture on top of pasta and add olives or feta or neither, depending on what you decide to put in and when.

Variations:
The original version of this recipe called for nutmeg rather than oregano, possibly with a little basil added, and it didn't have the red pepper or the olives. I called it my green pasta dressing and I liked to eat it with lime juice cordial (helps you absorb the iron, after all).

*The recipe in its current form is designed for one person, so take that 'half an onion' with a grain of salt. Metaphorical salt.