I made these tacos last year as well but with butternut squash instead.
This is very easy to make (especially if you already have a pack of Cool Chile Company tortillas).
Chop the pumpkin or squash into tiny cubes. Next time I'm gonna do really tiny cubes, about the same size as the chopped chorizo, so you get squash and sausage in every bite.
Toss the pumpkin in some olive oil, minced garlic, and ground chile. Roast in the oven for 20-30 minutes, until it starts to blacken at the edges.
To avoid over-cooking the chorizo and onions, wait until you know the pumpkin is cooked. Then fry the finely chopped chorizo and diced onion (I actually used shallots) in olive oil until the onion goes translucent.
Now add the pumpkin and fry a few minutes more, until all the flavours mingle.
Wrap in a warm corn tortilla, top with some homemade chipotle sauce (which I'm sure you just have lying around) and provecho!
I also garnished with white pickled onions, a variation on the traditional Yucatecan pink ones.