Clean and wash broccoli, divide into small florets and cook in boiling salted water for about 5 minutes. Pour broccoli onto a sieve and drain. Peel and finely chop the onion. Heat the fat in a saucepan. Fry the onion in it.
Dust with flour and sauté. Stir in stock and milk and simmer at low heat for about 3 minutes. Melt cheese in it. Prepare spaghetti in boiling salted water according to package instructions. Clean, wash and halve the tomatoes. Heat oil in a pan and fry the tomatoes in it for about 3 minutes. Season the sauce with salt and pepper. Add broccoli to the sauce and heat it up. Wash the chives and cut into small rolls. Put the pasta on a sieve and drain.
Heat oil in a pan and fry the tomatoes in it for about 3 minutes. Season the sauce with salt and pepper. Add broccoli to the sauce and heat it up. Wash the chives and cut into small rolls. Put the pasta on a sieve and drain. Serve with sauce and tomatoes on plates. Sprinkle with chives