Wash, clean and dice the tomatoes. Peel and finely dice garlic and onions. Cut the chilli lengthwise, remove seeds, wash and cut into rings. Heat oil. Sauté onions and garlic in it.
Steam the tomatoes and chillies briefly. Deglaze with chunky tomatoes and simmer for about 5 minutes. Season to taste with salt, pepper and lemon juice. Wash the basil and, except for something to garnish, chop finely and stir into the tomatoes.
Rinse the maties under running water, dab dry and arrange on the tomato sauce. Garnish with lemon wedges and basil. Italian baguette tastes good with it.