Cut peppers in half lengthwise; trim and remove seeds. Cut each half into thirds. Combine oil and lemon pepper; brush over peppers. Place beef top sirloin steak and peppers on grid over ash-covered coals. Broil 16 to 20 minutes, turning steak once and the peppers occasionally. Season steak and peppers with salt. Carve steak into thin slices and serve with grilled peppers.