Pumpkin is a winter squash. You may substitute a different variety, or even sweet potatoes. Just cube and roast until edges become browned, and the pieces are tender.
I cook my posole in the pressure cooker whether it is frozen or dried. Both require about 30 minutes under pressure. I try to avoid using canned hominy, but if I do, I rinse it thoroughly before adding to remove starch. When I shot the current photos, I used a beautiful New Mexico dried blue corn posole. I love the earthy flavor and beautiful color!
Hatch green chile is commercially available in many markets. Frozen fresh chile is preferable to canned.
You want to add cooked beans to the posole. If you have the time, and/or the desire to use dried beans, you will need to soak them and then cook them until they are tender by your preferred method. I usually use my pressure cooker to cook large batches of dried beans. Canned beans work fine in this recipe.
Crema (Mexican sour cream) is NOT vegan, and is listed as OPTIONAL for this reason!) Greek yogurt is a good option, and adds protein...
Macronutrients (approximation from MyFitnessPal): 384 calories; 14 g protein; 77 g carbohydrates; 7 g fat. These figures do NOT include garnishes. The pepitas (seeds) will add a little protein, but they're relatively low in fat and calories.