Simmer skate for 20 min in fish broth on low heat. Dress leaf salad with salad dressing and arrange on 4 plates. Pick apart cooked skate and spread evenly over lettuce.
Heat butter in a frying pan and add half the chopped onion. Brown and add salt, parsley, almond kernels and pepper. When it has finished steaming, add vinegar. Spoon this sauce evenly over the fish on each plate and bring to the table.