Add steak to a large ziplock bag with oil, lime juice, rice vinegar, cilantro, adobo sauce, chipotle peppers, salt, and black pepper.
Turn the steak to coat in the marinade evenly. Let side in the refrigerator for at least 1 hour, up to overnight.
Heat grill (or grill pan) to medium-high heat.
Remove steak from marinade and grill until desired doneness. I recommend about 4 to 5 minutes per side for medium rare.
Remove steak from heat and let rest 15 minutes before slicing.
While the steak is resting, add all ingredients for avocado salsa to a food processor or blender. Pulse until combined.
Serve steak immediately with avocado salsa.