Beef Fajitas

Ingredients

• 1/2 c. lite beer
• 1/2 c. oil
• 2 Tbsp. lime juice
• 1/2 small onion, thinly sliced
• 1 tsp. red pepper flakes
• 1/4 tsp. ground cumin
• 1/4 tsp. pepper
• 1 1/2 lb. skirt steak
• 1 Tbsp. oil
• 1 medium onion, thickly sliced
• 1 green pepper, cut into strips
• low-carb tortillas (purchased or homemade)
• guacamole
• salsa
• sour cream