Plantain Nacho Fries

Name: Plantain Nacho Fries
Ingredients: 3 ripe plantains (about 2 1/2 pounds) (see Cook’s Note); 3 green plantains (about 2 pounds); 1 tablespoon olive oil; 1 medium white onion, diced; 1 jalapeño, seeds removed, diced; 1 1/2 pounds ground beef (80/20); 2 cloves garlic, finely chopped; 1/4 teaspoon brown sugar; 1/4 teaspoon paprika; 1/4 teaspoon ground cumin; 1/4 teaspoon chili powder; 1/4 teaspoon garlic powder; 1/4 teaspoon onion powder; 1/4 teaspoon dried oregano; Kosher salt; 1/2 small red bell pepper, diced; 1/2 small green bell pepper, diced; 12 ounces evaporated milk; 6 ounces Gouda cheese, shredded; 6 ounces yellow Cheddar cheese, shredded; 2 1/2 teaspoons cornstarch; 2 tablespoons unsalted butter; Vegetable oil, for frying; 2 limes, juiced; 1/2 bunch cilantro, chopped, for serving; 2 avocados, sliced, for serving