• Peel and coarsely chop half the onion. Finely chop the remaining half and set aside for garnish. [Peel and coarsely chop 1 onion; finely chop 1 onion.]
• Cut a small corner from the ground turkey packaging and drain off any excess liquid. Transfer to a plate; pat dry with a paper towel.
• Trim the root ends and any coarse stems from the watercress.

In a large sauce pot over medium-high heat, warm 1 tablespoon oil until hot but not smoking. Stir in the coarsely chopped onion and smoky chili spice blend and cook until the onion is starting to soften, 1 to 2 minutes. Add the turkey, season with salt and pepper, and cook, stirring to break up the meat, until lightly browned but not yet cooked through, 2 to 3 minutes.
Add the butternut squash, tomato base, and 2 cups [4 cups] water, season with salt and pepper, and bring to a boil. Reduce to a simmer and cook, stirring occasionally, until the turkey is cooked through, the squash is tender, and the liquid has thickened slightly, 4 to 6 minutes. Remove from the heat, stir in the watercress, and season to taste with salt and pepper.
When the chili is almost done, prepare the remaining garnishes.

• Cut the lime into wedges.
• Coarsely chop the cilantro.

Transfer the chili to individual bowls and garnish with the finely chopped onion and cilantro. Serve with the lime wedges.