For the salsa, wash, quarter, seed and finely dice the tomatoes. Wash the coriander, shake dry and chop the leaves. Mix lime juice, salt, pepper and 1 pinch of sugar, fold in 3 tablespoons of oil.
Mix with tomatoes and coriander.
Grate cheddar and parmesan. Peel onion and garlic, dice finely. Heat 1 tablespoon of oil in a saucepan. Fry the onion, garlic and jalapeƱos in it. Add the milk, bring to the boil and simmer at low heat for 1-2 minutes.
Add the whole cheese and melt in it while stirring constantly. Season to taste with salt if necessary.
Arrange tortilla chips with cheese sauce and salsa. Sprinkle with chili flakes.