(Gluten-Free) Creamy Taco Mac & Cheese

3 tablespoons of butter
1/2 red pepper, diced
1/4 white onion, diced
2 tablespoons taco seasoning
3 cups coconut milk
3 tablespoons gluten-free flour
4 tablespoons natural yeast
2 cups cheddar cheese shredded
One cup mozzarella cheese, shredded
16 ounces gluten-free pasta
Garnish -
Sour cream
Green onion
Tomato