Preheat the oven to 220˚C/200˚C fan/gas mark 7. Chop 3 ripe tomatoes and 5 spring onions and place in a bowl. Deseed and chop 1 red pepper, 1 yellow pepper and 1 red chilli and add to the same bowl. Pick the leaves from a bunch of coriander, then chop the stalks and add to the bowl. Squeeze over the juice of 1 lime, drizzle with 1 tbsp olive or avocado oil and season with some salt and black pepper. Toss to coat. Heat 1 tbsp olive oil in a heavy pan over a medium heat. Stir in 2 crushed garlic cloves and cook for two minutes. Add 1 x 400g rinsed and drained tin of black beans with ½ tsp cumin, ½ tsp chilli powder and some salt and pepper. Heat through for 5-6 minutes, then smash the beans with a potato masher, leaving them slightly chunky. Spread 1 x 180g bag of tortilla chips out on a large rimmed baking tray. Spread over the beans and top with 200g grated Cheddar. Bake in the top half of the oven for 5-6 minutes until the cheese is melted. Scatter over the tomato mixture and top with 1 ripe sliced avocado and the coriander leaves.