In a large measuring cup, mix together vinegar, orange juice, olive oil, garlic, cumin, chili powder and salt. Place flank steak in a one gallon zip top plastic bag and pour marinade over it. Refrigerate for at least 6 hours or can be marinated overnight.

Preheat a grill or grill pan on medium high heat.

Cook the steak for about 4 to 5 minutes on each side for medium rare. Cook more or less depending on how done you like your steak.

Rest the steak before cutting for 5 to 10 minutes.

Cut steak on a cutting board in thin slips diagonally against the grain.

In a large bowl, whisk together the olive oil and lime juice. Add arugula and combine with the dressing. Season with salt and pepper to taste.

Place arugula on a large platter and place the peppers and avocado slices around it. Sprinkle cheese on top. Place sliced steak on top of salad. Garnish with the chopped cilantro.

Serve with salsa and sour cream, if desired.