1 ripe avocado, peeled, pitted and coarsely chopped
1 tablespoon finely chopped shallot
1 tablespoon lime juice
1/4 teaspoon crushed red pepper
1 1/2 teaspoons salt
1 pound ground chuck
1 teaspoon chili powder
4 whole-wheat hamburger buns
How to Make It
Preheat broiler to high; place a rack about 8 inches from heat source. Combine avocado, shallot, lime juice, crushed red pepper and 1/2 tsp. salt in a bowl. Lightly mash avocado with back of a fork to break up chunks. Cover with plastic wrap, pressing directly onto surface of guacamole, and chill until ready to serve.
Sprinkle beef with chili powder and 1 tsp. salt. Mix gently with your hands to distribute seasonings. Shape into 4 patties. Broil hamburgers until they reach desired doneness, turning once, about 8 minutes for medium-rare. Serve hamburgers on buns with guacamole on top.