Remove the avocado pulp from the skin with a spoon. Peel garlic and chop finely. Briefly mash the avocado, yoghurt, stock, garlic and lemon juice. Season to taste with salt and pepper.
Wash the meat and dab dry. Heat the oil in a pan, add the meat and fry it all around for 2-3 minutes. Remove and season with salt and pepper. Clean and wash the salad. Pick the frisée salad into bite-sized pieces.
Wash and halve the tomatoes. Clean and clean the mushrooms and cut into wafer-thin slices. Mix salad, tomatoes and mushrooms, season with salt and pepper. Cut meat into pieces and arrange on a plate with the salad.
Add the avocado yoghurt sauce.