Cook the beans as per on pack instructions. Drain and set aside.
In a large frypan, heat oil and cook onion for 4-5 minutes until softened. Add garlic and capsicum and cook for another 4-5 minutes, stirring often. Add chilli powder and cook for 1 more minute. Take off the heat.
Into the bowl of a food processor, add the cooked pinto beans, oregano, vinegar, salt and pepper. Pulse to combine then add ¼ cup water and the onion mixture cooked in step 2. Process until smooth, taste and adjust seasoning with more salt and pepper if required.
To assemble nachos: Preheat oven to 190ºC, fan forced. Assemble corn chips in a large tray and dollop spoons of bean dip all over chips. Sprinkle with cheese and jalapenos if using and bake in the oven until cheese is melted and bubbling for approximately 10 minutes. Remove from oven and top with tomato, sour cream, avocado, spring onions and coriander. Serve immediately.