Easy Vegetarian Enchiladas

Ingredients

• 2 tablespoons vegetable oil
• 1/2 small onion, diced
• 2 cloves garlic, chopped
• 2 teaspoons ancho chile powder
• 1 teaspoon ground cumin
• cayenne pepper, to taste
• 2 cups water
• 1 (15-ounce) can tomato purée
• 1/2 teaspoon kosher salt
• 1 (10-ounce) package frozen chopped spinach, thawed
• 1 (15-ounce) can pinto beans, strained and rinsed
• 4 ounces cheddar cheese, shredded, divided
• 4 ounces Pepper Jack cheese, shredded, divided
• 1/2 cup sour cream, divided
• 3 scallions, sliced, divided
• 1 1/4 teaspoons kosher salt, plus more, to taste
• 12 (6-inch) corn or flour tortillas
• juice of 1/2 lime