In a small bowl, whisk together the chili powder, salt, granulated garlic and onion, cumin, oregano, black pepper, and a pinch of cayenne (if you like heat).
Heat the oil in a large skillet over medium-high. Add the ground beef, sprinkle in all of the spice mix, and break the meat into small pieces with your spoon. Cook, stirring now and then, until it’s fully browned (about 8 minutes). Drain off any excess fat.
Return the drained beef to the pan, stir in the refried beans and ¼ cup water, and warm through until the beans loosen up and everything is hot. Keep this mixture over low heat while you prep the chips.
Preheat your oven to 350 °F. Spread the tortilla chips in a single layer on a rimmed baking sheet or oven-safe platter. Slide them into the oven for about 5 minutes, just until you smell their toasty aroma.To get perfectly crisp, layered nachos, I like using a large baking tray like this — it gives you plenty of space to spread everything out evenly. Pull the chips out and sprinkle half of the cheddar and Colby Jack over them. Let the residual heat soften the cheese for a minute, then spoon the beef-bean mix on top. Layer some more chips on top and again spoon over the beef-bean mix, do this once more. Finish with the remaining cheese and return to the oven for another 5 minutes, until it’s all melted and bubbly.Freshly grated cheese melts better than pre-shredded — I use this box grater to get perfect fluffy shreds for loading up the nachos. Scatter the pico de gallo, chopped cilantro, and jalapeño slices over the hot nachos. Add any extras you love, guacamole, sour cream, olives, green onions, then serve straight from the pan. Enjoy while they’re warm and cheesy!