1. Wipe the mushrooms clean with a kitchen paper or mushroom brush.
2. Cut the onion into pieces. Heat a dash of oil in a frying pan and fry the onion gently. Squeeze the clove of garlic over it.
3. Coarsely crush the mushrooms in a food processor. Add the mushrooms to the onion and garlic in the pan and fry for a few minutes over a high heat, stirring occasionally.
4. Put the mushroom mixture in a sieve over a bowl and leave to drain and cool.
5. Crumble the bread.
6. Finely chop the cashew nuts.
7. Add the breadcrumbs, cottage cheese, mustard, chopped cashews, freshly ground pepper and breadcrumbs to the mushroom mixture.
8. Turn the mixture into 4 small flat burgers by hand.
10. Heat a dash of oil in a frying pan. Fry the mushroom burgers until nicely browned on both sides.
Wash the lettuce.
12. Cut the buns in half. Top the buns with a leaf of lettuce and place the burgers on top. Garnish with slices of fried mushroom. Enjoy your meal!