Place the curd in the middle of a damp tea towel. Take the corners of the cloth together and squeeze out some of the curd by turning it (approx. 50 ml of liquid should come out). Put the quark in a bowl.
Wash the herbs, dab dry, pluck flags or leaves from the stems and chop finely, except for a little to garnish. Pluck the trout and, except for a few pieces for garnishing, mix carefully with the herbs, mustard and quark.
Season with salt and pepper. Serve the spread, garnish with herbs and pieces of trout. Serve with brown bread or pumpernickel.