For the Pico-Guac, to a bowl, add the juice of 2 limes, the onion, garlic, and jalapeno peppers and let stand 5-10 minutes. Add cumin, cayenne sauce, tomatoes, avocados, cilantro or parsley and mash up, then adjust salt. Transfer to serving bowl and top with scallions.
For squash, preheat oven to 450˚F and arrange the squash on a baking sheet and spray with oil. Season with salt, pepper, nutmeg, cinnamon and chili powder. Roast to tender and brown at edges, 25 minutes. Reduce heat to 325˚F.
In a skillet over medium-high heat, brown and crumble the chorizo in olive or vegetable oil, then add onions, garlic and peppers and cook until onions are translucent. Add half a cup of water and let it absorb.
Line the shells with cheeses and roast to toast, 5 minutes.
Combine squash with chorizo and transfer to serving dish.
Tacos: cheese-lined tacos filled with chorizo and squash, top with cabbage, lime, Pico-Guac, pickled jalapeño rings and pepitas.