For the Perch
Slice the perch into 4 fillets with a sharp, thin knife. Place the fillets in a bowl and all of the marinade ingredients. Mix carefully. Let the perch marinate for around 30 minutes. Heat a stick-free saucepan with raised ridges and place the perch on it and begin to cook. After 4 minutes turn the fish over carefully so that it remains in one piece. Cook for another 4 minutes and then remove the fillets from the pan.
For the Caesar Salad
Place the anchovies and garlic in a blender and blend well. Add the mustard and the mayonnaise and blend for 3-5 minutes at a low speed. Then add the vinegar and blend again. In the meantime, mix the oils in a cup. While the blender is working, gradually add the mixed oils. Add salt and pepper to balance the taste. Serve the perch with the Caesar sauce and accompany with vegetables or salad.