For the sauce, peel and pit the avocados, chop coarsely and mash. Season with salt, pepper and lemon juice.
Peel the asparagus and cut off the ends. Salt and pepper the salmon and fry on both sides. Halfway through cooking, add the tomatoes and fry.
At the same time, cook the asparagus in salted water until firm to the bite, drain.
Serve the salmon with the asparagus and tomatoes and garnish with the avocado sauce.