Sauté the fish medallions in some olive oil for 3 minutes on each side. Season with salt and pepper. Set the pan aside and keep the medallions hot.
Drain the small red peppers but keep the drained liquid so that it may be used to deglaze the medaillons that are still in the frying pan. Heat this liquid so that it starts reducing and season it. Add the liquid from the medallions.
Put the red peppers, the mixed liquid, 2 garliccloves (degermed), some salt and a pinch of chilli powder in a blender.Mix for 1 min and set this coulis aside in a bain marie.
Use large plates to arrange the dish. Place a monkfish medallion in the center of each plate. Put some mushrooms in the center of each medallion along with two basil leaves on each side. Decorate with surrounding coulis. Delicious.