In a medium mixing bowl blend Bisquick, cornmeal, salt, and lemon-pepper together. In a separate medium mixing bowl beat egg well, add beer and minced onions, mix well. Cut the catfish into 2-inch cubes or strips. Heat the vegetable oil. Roll the catfish into the dry mixture, then dip into the beer-egg mixture, then back into the dry mixture. Place dipped catfish into the deep-fry, cook until golden brown.