Cut the leek and carrots into slices and sauté them together in a pan, season with salt and pepper, remove and keep warm.
Cut the salmon into cubes, fry the crabs and the chopped garlic in the olive oil. Steam everything very carefully so that it doesn`t overcook. Add the leek and carrots, stir in the tomato paste and season with your choice of spices.
Mix everything together (i.e. pasta, fish & vegetables) in a large bowl. Finally garnish with finely chopped basil.