Step 1: Preheat your oven to 375°F (190°C) and lightly grease a 9x13 inch baking dish.
Step 2: In a medium saucepan, heat 1/4 cup of oil over medium heat. Whisk in the flour and cook for 1 minute to create a roux.
Step 3: Add the chili powder, cumin, garlic powder, onion powder, and tomato paste. Whisk constantly for 30 seconds to toast the spices.
Step 4: Slowly whisk in the vegetable broth until smooth. Simmer for 5-7 minutes until the sauce thickens slightly. Season with salt.
Step 5: In a small skillet, heat a tablespoon of oil over medium-high heat. Quickly fry each tortilla for 3-5 seconds per side just to soften. Drain on paper towels.
Step 6: Dip a softened tortilla into the sauce, lay it flat, and fill with about 3 tablespoons of the cheese blend and a sprinkle of onions.
Step 7: Roll the tortilla tightly and place it in the baking dish. Repeat for all tortillas.
Step 8: Pour the remaining sauce over the rolled enchiladas and top with the remaining cheese. Bake for 20-25 minutes until the cheese is melted and bubbly.