Grilled Steaks with Red Pepper Sauce

• 4 red bell peppers, quartered, stem and seeds removed
• 2 yellow onions, sliced in rounds (¼ in.)
• 2 garlic cloves
• olive oil, to drizzle and rub
• 32 oz flank steaks
• ½ tsp salt
• ¼ tsp ground black pepper

Red Pepper Sauce

• 4 oz olive oil
• ½ tsp salt, to taste
• ¼ tsp ground black pepper