Start by chopping the onion. Add the olive oil and onion to a large pan and sauté over medium heat until the onion is soft and transparent. This should take about 5 minutes.
Now drain, but do not rinse the black beans, allowing some of the starchy liquid to remain coating the beans. Add the beans and diced tomatoes to the pan, along with the chilli powder, cumin, garlic powder, and salt.
Stir and simmer the mixture until it thickens, about 10 minutes.
Begin preheating the oven to 180°C.
Slice the tomatoes in half, thinly slice the jalapeño, and chop the coriander.
Line your baking tray with baking paper.
Spread a layer of nachos over the baking tray in a single layer, trying not to overlap them. Spoon about half of the beef and beans over the nachos, then sprinkle half of the grated cheese over the top. Repeat with one more layer of nachos, beef, and cheese.
Bake the nachos, meat, and cheese for 5-7 minutes, or until the cheese is fully melted and the chips are just beginning to turn golden brown on the edges. Remove the nachos from the oven and add your sour cream. Sprinkle the tomatoes, sliced jalapeño, and chopped coriander over the top.
Servings 4