Drain black beans, using a sieve, drain off excess salt. Peel and chop half a small red onion into dices. Drain off sweetcorn and set aside.
Heat oil on a frying pan and add in onion, once frying, turn down to medium, allowing to sizzle for 2-3 minutes while stirring.
Add in the drained beans, along with 1 tbsp tomato paste, a splash of water, and remaining black bean mix seasonings. Turn the heat up to make it bubble, then turn down to medium and cook for 5-8 minutes, set aside.
Wash a small bit of mixed leaves, and prep the guac and sour cream (if prepping yourself).
Empty a large pack of nachos of choice into 2 separate bowls. Add some lettuce on top, a bit of blackbean mix on, as well as sweetcorn and jalapeños.
Then top off with some guacamole, and sour cream (if using). Serve and enjoy while the chips are still crunchy!