Preheat oven to 350 degrees F (175 degrees C). Grease a 2-quart casserole dish. Mix milk, sour cream, Cheddar cheese, eggs, butter, salt, and black pepper in a bowl until well combined. Stir matzo farfel into sour cream mixture and pour into prepared casserole dish. Bake in the preheated oven until casserole is set and top is lightly browned, 30 to 40 minutes.