MIX the first six spice ingredients (oregano, pumpkin spice, cumin, garlic powder, chili powder, and ancho chili powder) in a small container and set aside.
CUT pumpkin or squash in half, then remove and discard seeds.
BRUSH olive oil on the pumpkin or squash, then place on a sheet pan, cut side up, and bake at 400°F for 20 minutes or until fork tender. (If using butternut squash, adjust baking time to 40 minutes.) Let cool, then cut it into ¼-inch pieces.
ADD 1 tablespoon of olive oil to a large pot. Sauté the chopped onions, carrots, celery, and bell pepper for 2 minutes or until tender. Next, add the chopped garlic and cook for 30 seconds, then season with salt and pepper.
PLACE the sautéed vegetables in a small bowl and set aside.
ADD 1 tablespoon olive oil to the pot, then add the ground lamb and cook until brown. Then add half of the spice mixture to the lamb along with salt and pepper, then stir.
ADD the vegetables back to the pot with the lamb. Add tomato paste, fire-roasted tomatoes, beef broth, the remaining spice ingredients and stir. Add salt and pepper and stir. Bring to a boil, reduce to a simmer, cover, then cook for 15 minutes.
ADD cooled pumpkin or squash to the chili and cook for 5 minutes. Taste and add more salt and pepper if needed.
GARNISH with chopped parsley and chives, then enjoy!