Dice the onion finely and prepare the jalapeños, setting them aside. Bring a large pot of salted water to a boil and add the pasta, cooking it until just firm (al dente). While the pasta cooks, you'll have time to prepare the remaining components. Once cooked, reserve 1/3 cup of the pasta water before draining the pasta completely.

Heat the olive oil in a large skillet over medium-high heat until shimmering. Add the diced onion and cook for 2-3 minutes until softened and fragrant. Add the ground beef, breaking it up as it cooks, and continue cooking until fully browned and no pink remains. Drain excess fat if needed, leaving just enough to coat the pan for flavor. I like to let the beef get a little caramelized on the edges—this builds much deeper flavor than just cooking it until it's gray.

Add the taco seasoning, smoked paprika, garlic powder, and tomato paste to the browned beef. Stir constantly for about 2 minutes to bloom the spices and cook out the raw tomato paste flavor. This short cooking time is crucial—it releases the aromatic compounds in the spices and prevents the tomato paste from tasting flat or bitter. Pour in the beef stock and fire-roasted diced tomatoes with their juices, then add the prepared jalapeños. Bring to a gentle simmer and cook for 10-15 minutes, allowing the flavors to meld and the sauce to thicken slightly.

Preheat your oven to 400°F/200°C. In a large bowl, combine the cooked pasta from Step 1 with the beef mixture from Step 3, along with the reserved pasta water. The pasta water acts as a binder and keeps the bake creamy as it cooks. Stir in 1.5 cups of the freshly shredded sharp cheddar cheese, reserving some for optional topping. Spray a 9x13 inch baking dish with oil spray and pour the pasta-beef mixture evenly into the dish.

Sprinkle the crushed tortilla chips evenly over the top of the pasta mixture, creating a thin, even layer. The chips will toast and crisp up in the oven while also absorbing some of the flavors from the sauce underneath. Bake uncovered for 20 minutes until the top is golden brown and the mixture is bubbling at the edges.

Remove the bake from the oven and let it rest for 2-3 minutes—I always do this so the cheese sets slightly and the whole dish holds together better when plated. Serve directly from the baking dish or scoop into bowls, garnishing generously with fresh cilantro, diced red onion, fresh diced tomato, and sliced avocado. Serve with sour cream on the side and fresh lime wedges for squeezing over top.