1Heat gas or charcoal grill. Sprinkle both sides of beef with seasoned salt, garlic-pepper blend, chili powder and oregano.
2Place beef on grill over medium heat. Cover grill; cook 8 to 9 minutes, turning once or twice, until desired doneness. Add buns, cut sides down, for last 4 minutes of grilling or until toasted.
3Cut beef crosswise into thin slices. Spread about 2 tablespoons salsa on bottom of each bun. Top with beef, avocado, cheese and tops of buns.