Empty the cans of beans, chickpeas and lentils into a strainer, and rinse under a cold tap. Drain well and place into the bowl of the slow cooker.
Tip in the nachos sauce, rise the bottle with ¼ cup of water and add that to the beans.
Add the chillies, onion, cumin powder, paprika, chilli powder, lemon juice and salt.
Stir very well, place the lid on and turn the slow cooker to high. Cook for 2 hours.
Remove the lid and give a quick stir, cover and cook for another 30 minutes.
Taste for seasoning and adjust if necessary. Squeeze in a little extra lemon juice to taste.
Serve over corn chips. Enjoy as is or, top with sour cream, cheese, coriander leaves or spring onions.