With a small knife, pierce top and sides of brisket 1-inch deep every 2-inches. Insert garlic slice in each cut.
Place meat, fat side up, in shallow baking pan. Pour 1 cup beer over meat. Cover with foil and bake at 300ºF for 2 hours.
Remove meat from pan. Drain liquid, reserving 1/2 cup. Return meat and reserved liquid to pan.
Combine remaining beer, barbeque sauce and green chilies. Pour over meat. Continue baking, uncovered, for 1 hour or until meat is tender.
With knife slanted at 45º angle, carve meat across the grain into thin slices. Serve with remaining sauce.
Servings: 8