Cheesy Taco Beef and Kale Bowls with Spiralized Sweet Potatoes

Name: Cheesy Taco Beef and Kale Bowls with Spiralized Sweet Potatoes
Ingredients: 2 tablespoons extra virgin olive oil; 2 medium sweet potatoes (peeled, Blade D, noodles trimmed); salt and pepper; 4 cups chopped curly kale; 1 small white onion (diced); 1/2 diced green bell pepper; 2 garlic cloves (minced); 1 tablespoon tomato paste; 1 pound lean ground beef; 1/8 teaspoon cayenne pepper; 1 teaspoon chili powder; ¼ teaspoon paprika; ¼ teaspoon dried oregano; ¼ teaspoon onion powder; ½ teaspoon cumin; ¼ cup broth (beef or chicken); ½ cup shredded cheddar cheese; 1 large avocado (pitted, peeled, and sliced); optional to garnish: sliced scallions