Cut the mushrooms into plates (chop the legs).
Cut the onion into thin half rings.
Sausages are also half-rings.
Separately fry the onion until golden brown.
Then fry the mushrooms (add salt).
Remove excess oil, cool.
Boil the string beans in salted water, cool (the main thing is not to overcook).
Wash the red beans.
Mix all the ingredients
Season the sauce in a ratio of 2 tablespoons of mayonnaise + 1 teaspoon of ketchup.