In a medium bowl, add grated cheese, chopped garlic and oregano.
Add sour cream and mix thoroughly until all ingredients are mixed together.
Place the fish piece in a baking dish and cover the top with the sour cream mixture prepared earlier. Season with pepper and salt to taste and let sit for about 20 minutes.
Then place the perch dish in the oven preheated to 180 °C for 25 minutes. The finished perch should be slightly golden in color, and the cheese casing should melt.