Preheat the broiler.
Briefly rinse the carp inside and out with tap water. Dab with kitchen towel. Season well with salt inside and out and season with pepper.
Grease a thin, rectangular ovenproof dish with light butter or butter. Remove the skin from the garlic clove and press it through a garlic press or chop it finely. Sprinkle on the bottom of the dish.
Place the carp in the mold with the belly flaps folded out. Make deep incisions in the back, at one-inch intervals.
Heat the butter or alternatively light butter with the parsley in a small pan. Season vigorously with salt and season with pepper. Pour over the carp.
Put the pan into the grill so that the distance between the carp and the heating rods is at least 120 mm. Grill the carp for 20 minutes, if necessary cover it with aluminum foil beforehand.
Finally, cook in the oven at 250 °C for another 10 minutes.
Serve with boiled, peeled potatoes and curd cheese seasoned with horseradish.