Morcilla de Burgos with onion and rice, you cut it up and fry it in little olive oil. Do not boil it first, you lose the flavor. Spanish sausage is different from English sausage. The other kind of morcilla, you take it out of it's sausage wrapping/casing and you fry it up in a little olive oil with pasas (raisins) and pine nuts. I like to cook them until they are a little brown and crispy on the outside. I hope this helps!