1 (5 1/2 pound) corned beef brisket with spice packet 7 small potatoes, peeled and diced 4 medium carrots, peeled and diced 1 medium onion, diced 3 cloves garlic, chopped Preheat the oven to 300 degrees F (150 degrees C). Place corned beef brisket in the center of a roasting pan. Arrange potatoes and carrots around the sides, then scatter onion and garlic over top….