Bean Tostadas {20-Minute Vegetarian Dish!}

Ingredients

• 1 tbsp olive oil, divided
• 1 green pepper, sliced
• 1 red pepper, sliced
• 1/2 red onion, sliced thin
• 30 oz canned black beans, drained and rinsed
• 1/2 cup salsa (any kind will work)
• Salt and pepper
• 2 tbsp water or broth (more as needed)
• 8 corn tortillas