Chorizo, Potato and Avocado Burritos

fresh Chorizo sausage links

potatoes, cubed (like Yukon Gold)

red bell pepper, cut into short, wide strips

large onion, cut into short, wide strips

olive oil

coarse salt and black pepper

ripe avocados

(12-inch) flour tortillas

aged white cheddar cheese, shredded

butter, for pan frying

sour cream or crema, for serving