Cook garlic in oil in small nonstick frying pan over low heat until tender, about 5 minutes. Add onions; increase heat to medium low and continue cooking until onions are crisp-tender, about 5 minutes. Remove from heat; cool thoroughly. Meanwhile, trim excess fat from boneless beef top sirloin steak. To cut pocket in steak, make a horizontal cut through the center of the steak, parallel to the surface of the meat, about 1 inch from each side. Cut to, but not through, opposite side. Spoon cooled stuffing into pocket, spreading evenly. Secure opening with wooden picks. Place steak on grid over medium-low coals. Cover. Grill 26 to 32 minutes for rare 140F to medium 160F or to desired doneness, turning once. Remove picks; carve into 1/2 inch slices.
A boneless beef top sirloin steak will yield four 3-oz cooked trimmed servings per pound.
The beef top sirloin steak may also be cooked uncovered over medium low coals. Grill 30 to 40 minutes for rare to medium, turning frequently. If steak appears to be drying out, brush lightly with olive oil.
Cajun Country -- New Iberia, Louisiana