Heat 2 tablespoons of the oil in a large Dutch oven or soup pot over medium heat.
Add the ground turkey, and cook completely, breaking it up with a fork as it browns, about 10 minutes.
Remove the turkey to a bowl or a plate.
Add the remaining 1 tablespoon of oil to the pot, stir in the onions, poblanos and jalapeos, and cook until the onions are translucent and the peppers are slightly softened, about 4 to 6 minutes.
Add the garlic and cook 1 minute more.
Add the browned turkey to the pot, along with the tomatillos, chicken stock, squash, lime juice, cumin, chipotle powder and oregano, and cook for approximately 8 to 10 minutes, or until butternut squash is cooked through.
Serve garnished with cilantro, if desired.