Peel and finely dice the onion and garlic. Clean the chillies, carve lengthwise, remove seeds, wash and chop finely. Wash and roughly dice the tomatoes.
Heat the oil in a pot. Sauté the garlic and onion in it. Sweat tomato paste briefly. Add tomatoes and chillies and fry. Season with salt and pepper. Pour in about 1/4 l water, bring to the boil.
Stir in broth. Simmer open over medium heat for about 10 minutes.
Meanwhile cook the spaghetti in plenty of boiling salted water for about 8 minutes until al dente. Drain.
Wash basil leaves and cut into strips. Mix spaghetti with tomato sauce. Fold in basil. Arrange everything.