Heat a 12-inch skillet over medium heat. Add 1 tsp vegetable oil. When shimmering, add the diced onion and cook 3–4 minutes until softened. Add the minced garlic and cook 30 seconds until fragrant.

Brown beef

Increase heat to medium-high and add the ground beef to the skillet. Break it up with a spoon and cook until no longer pink, about 6–8 minutes.

Season and simmer

Drain excess fat if desired, leaving a little for flavor. Stir in chili powder, cumin, paprika, salt, pepper and tomato paste. Mix thoroughly so spices coat the beef. Pour in 1/4 cup beef broth (or water), reduce heat to medium-low and simmer 3–4 minutes until mixture is slightly thickened and well combined. Taste and adjust salt/pepper. Remove from heat and keep warm.

Chips & cheese

Assemble nachos

Preheat oven to 400°F (200°C). On a large rimmed baking sheet or oven-safe platter, spread half of the tortilla chips in an even layer. Sprinkle with half of the cheddar and Monterey Jack cheeses. Spoon the cooked beef evenly over the cheese layer. Top with remaining chips and then scatter remaining cheeses over the top so cheese will melt through both layers.

Melt cheese

Bake on the middle rack for 6–9 minutes, until cheese is fully melted and edges of chips are golden. For extra browning, switch to broil on high for 30–60 seconds—watch carefully to avoid burning.

Fresh toppings

Immediately after removing nachos from the oven, evenly scatter diced tomatoes, sliced green onions, jalapeño slices and chopped cilantro over the hot cheese so toppings warm slightly but remain fresh.

Sauces & garnish

Serve the nachos hot with bowls of sour cream and salsa on the side. Offer lime wedges for squeezing over individual portions. If desired, dollop sour cream or drizzle salsa over the top before serving.