Combine salsa, olive oil, lime juice, chipotle peppers in adobo sauce and cumin powder in a large zip-top bag or bowl.
Add the beef and toss with marinade until fully coated.
Close or cover with plastic wrap and refrigerate for 2 hours. If short on time, 30 minutes will do. Any amount of marinating time is better than none!
To make the skewers
While beef is marinating, soak the wooden skewers in water for at least 30 minutes before grilling. This will help prevent them from burning on the grill.
Remove steak from marinade and discard any excess.
Carefully thread the steak and veggies on two bamboo skewers that are about half an inch apart. This will help them cook more evenly and makes them easier to handle. I like to alternate threading the meat and the veggies - it just looks so pretty!
Spray the skewers lightly with cooking spray.
Grill skewers over direct heat for about 8 to 10 minutes, turning when each side has achieved beautiful grill marks and is slightly charred.
Remove skewers from grill and let rest for 5 minutes before eating.