Vegetarian Fajitas

• 1 small brown onion, thinly sliced
• 1 red capsicum, sliced
• 1 yellow capsicum, sliced
• 400 g tin black beans, rinsed & drained
• 1 tsp chilli powder
• 2 tsp paprika
• 1 tsp garlic powder
• 2 tbsp extra virgin olive oil
• 6 mini flour tortillas
• 1 avocado, smashed
• 1 lime, quartered
• 2 tbsp coriander, chopped