Cook the onion and chorizo. Heat your oven to 430F/220C. Set a large, high sided ovenproof skillet or pan over medium-high heat, and drizzle with 1 tablespoon of olive oil. Add the diced onion, chopped or crumbled chorizo and 1 teaspoon of salt. Cook, stirring, for a few minutes, or until the onion is softening and the chorizo has released its lovely oil.
Add the spices. Pour in the chopped pickled jalapeños, 1 teaspoon of chili powder, 2 teaspoons of ground cumin, 2 teaspoons of smoked paprika, 2 teaspoons of dried oregano, the crushed garlic and a good grind of black pepper. Stir through the onion and chorizo for another couple of minutes.
Cook the beef. Add the ground beef to the pan, breaking it up with your spatula or wooden spoon. Cook, stirring occasionally until the beef has browned (five or so minutes).
Add the tomatoes, beans and corn. At this point, pour in your canned tomatoes, drained black beans, corn and 3/4 cup of water (I like to refill the empty tomato can with water to get any tomatoey residue out). Stir through the beef and bring to a simmer. Lower the heat and simmer for about 10 minutes, just to thicken up the sauce.
Arrange the tater tots. Once the chili has thickened a little, give it a taste, then season with a little more salt and pepper if you think it needs to. Scatter half the cheese on top, then arrange the tater tots on top of the cheese. You can make a pretty circular pattern like I have in the photos in the post above, or arrange them a bit more rusticly. It's up to you!
Bake the casserole. Scatter the remaining cheese on top of the tater tots, then transfer the pan to the oven. Bake for 25 to 30 minutes, until the tater tots are deeply golden and the chili is bubbling.
Make the whipped avocado. While the casserole bakes, scoop the flesh of your avocado into a small bowl. Add the juice of 1 lime, a good handful of chopped cilantro and a pinch of salt. Use a fork to mash everything together, then taste and add a little more salt or lime juice if needed. Set aside.
Garnish and serve. Dollop the sour cream onto the baked casserole, then spoon the whipped avocado on too. Scatter with more cilantro and the chili powder, then serve while hot.