Mix the garlic powder, onion powder, pepper, salt, sugar, and lemon juice in a bowl. Cube the top sirloin steaks and marinate in the mixture for at least 2 hours.
Skewer the meat. On a grill set to medium heat, grill the kabobs for about 2 minutes per side, or until they reach your preferred doneness..
Remove from the grill and quickly roll kabobs into pistachios. Serve immediately.