Potatisgratäng: Mediterranean pasta

My love for cooking have started from a simple interest how to make it right. Googling each time before boiling rice was annoying . Occasionally, one of William Pokhlyobkin's books have found me - The Secrets of a Good Cuisine.

For the first time I have read how to stew, boil, fry, mix properly. This pasta was made according to the rules of Good Cuisine.

Ingredients (serves 4):

250 g shrimps (preferably unpeeled), frozen works as well
250 g mussels, frozen works as well
2-3 tomatoes
2 onions
2 tbsp balsamic vinegar
olive oil
pasta (I like Penne Rigate for it)
salt, pepper,
1 tbsp dried basil

Procedure:

Place tomatoes in a bowl, poor very hot water over it and leave for a while.
Peel and chop onions finely.
Heat the frying pan, add olive oil. Important, it is absolutely wrong to add cold oil into the frying. mixture. Try to calculate how much oil need overall and heat it from the beginning.
How to guess if oil is ready? When a little smoke starts to evaporate from oil, add a pinch of salt. You will hear the squeaking noise. Oil is ready.
Place the onions into the hot oil. Fry around 5 minutes or more until transparent, steering occasionally
Add seafood, steer the mixture. Fry around 10 minutes, add balsamic vinegar.
Peel the tomatoes from skin, chop finely. Add to the pan and fry 10 minutes, then reduce heat to medium, after 10 more to small.
Start boiling pasta. Preheat the water, when boiled add a pinch of salt and a tsp of olive oil. Place pasta inside. Boil according to the box instruction (usually 10-15 minutes).
When pasta is ready, drain from water, add a small piece of butter and mix.
After the sauce ready, add some dried basil and steer together.
Serving. Put the pasta onto the plate, leaving a small valley in the centre, poor the sauce on top. Sprinkle some Parmesan cheese, if you like.