Heat a large skillet over medium heat. Add the ground beef and cook, breaking it up with a spatula, until browned and cooked through, about 5–7 minutes.

Add diced onions and minced garlic to the skillet and cook for 2–3 minutes, until softened.

Stir in chili powder, cumin, paprika, salt, and pepper. Mix well to coat the beef evenly.

Add tomato paste and water, stirring to combine. Simmer for 2–3 more minutes until slightly thickened. Remove from heat.

Assemble and Bake Nachos

Preheat oven to 375°F (190°C).

On a large baking sheet or oven-safe platter, spread half of the tortilla chips in an even layer.

Top with half of the beef mixture, cheddar cheese, Monterey Jack cheese, and jalapeños (if using).

Repeat with the remaining chips, beef, and cheese.

Bake in the preheated oven for 10–12 minutes, or until the cheese is melted and bubbly.

Garnish and Serve

Remove the nachos from the oven and sprinkle with diced tomatoes, green onions, and chopped cilantro.

Serve warm with dollops of sour cream and guacamole on top or on the side.