Preheat oven to 400 degrees F.
In a large frying pan over medium-high heat, brown steak/beef and chorizo, stirring (5 minutes). While meat is cooking, chop onion and mince garlic.
Add onion and all but 1/8 tsp cumin to pan. Stir often until onion is soft (4 to 5 minutes). Reduce heat to medium and stir in 1 1/2 cups salsa. Simmer until thick, stirring occasionally (8-10 minutes).
While steak mixture simmers, combine black beans, 3/4 cup water, oregano, 1 tsp garlic, and chiles in a small saucepan. Bring to a boil over high heat, then reduce heat to medium and simmer until all but about 1/4 cup liquid has evaporated (10 minutes).
While the beans simmer, make guacamole: Pit and peel avocado. In a bowl, mash avocado with remaining 1 tbsp salsa, remaining 1/8 teaspoons cumin, remaining garlic, and the lime juice. Stir 1 tbsp cilantro into guacamole and add salt to taste.
Line a large, rimmed baking pan with parchment paper. Arrange chips in a 12-in.-wide circle. Sprinkle with cheese. Bake until cheese melts (3 to 4 minutes). While chips are baking, arrange lettuce around rim of a large serving platter (at least 16 inches wide).
With a wide spatula, loosen chips from parchment. Carefully lift parchment from pan, then slide chips off paper into center of platter. Spoon meat mixture over chips.
Sprinkle pickled jalapeno slices over chips. With a slotted spoon, top with beans. Spoon guacamole over center of nachos and sprinkle with remaining 1 tablespoons cilantro.