Makes 24 tamales
In a 12-inch skillet, heat olive oil and sauté the huitlacoche, onion, garlic and bay leaves. Add the huitlacoche mixture to a blender and pulse once or twice. The consistency should remain chunky.
Mix blended huitlacoche mixture with masa. Season to taste.
To assemble the tamales, divide the masa into 24 equal portions. Open the corn husks and place 1 portion of dough in the center of each corn husk. Fold over the sides of the husk and secure tamale with a piece of string. Repeat the process until all the dough is finished.
In a double boiler with a steamer insert, steam the tamales for 40 to 45 minutes. Set aside to cool for 5 minutes.
To serve, remove husks. Garnish with corn relish and Cotija cheese.