Brush off the mushrooms and cut them in slices.
Heat the sunflower oil in a frying pan, fry the mushrooms and keep them heated.
Rinse chervil and pluck off leaves.
Mix the yogurt-based mayonnaise with the truffle tapenade.
Grill the beef burgers for approximately 6 minutes.
Cut open the bun and put the rocket and burger on heal of bun. Top with fried mushrooms and garnish with truffle-mayonnaise and chervil. Close burger with crown of bun.