In a large pot, bring water to a boil. Cook pasta with salt until al dente (just cooked).
Drain off and rinse them. Drain in a colander. Set aside.

Grease tomatoes and roast them on flame.
Cool and blend them together to a puree. Set aside.

Heat a pan add oil and fry garlic and chilli flakes until aromat.

Add onions and saute until golden.
Sauté all steamed vegetables and mushrooms too

Pour the puree and add salt. 
Mix well and cook until it reaches a desired consistency. Make sure the sauce is not watery. Taste the sauce and adjust salt as needed. Add oregano.

Add the pasta. Toss well until mixed.

Garnish with herbs. Serve hot pasta in red sauce.