Glaze the sliced onion and garlic in a frying pan over medium heat. Add the minced beef and chilipowder and brown and break it up with a fork or spatula. When the beef is cooked 3/4 of the diced tomato and the beans and let simmer for about 10 minutes over a low heat.
Take an heatproof plate and make a royal base of chips. Put a couple of spoons of the beef and beans mix on top of it and on top of that half of the grated cheese. Add some more chips on the cheese and repeat the beef-beans and grated cheese sequence again. Sprinkle some of the finely sliced red chili on top of mount Nachos and then put the plate in the oven. Grill for a couple of minutes until the cheese has melt and gets that smokey color. Pay attention, because it burns fast if left unattended.
Remove the nacho plate from the over and finish off by sprinkling the spring onion and the last of the diced tomato over the Nachos Dudos. Serve the sour cream and guacamole next to the mountain of goodness for dipping.