Step 1

Heat 1 1/2 teaspoons of the oil over medium-high heat in a large Dutch oven. Add the turkey and cook, breaking up chunks with the side of a wooden spoon, until browned, about 5 minutes. Push the turkey to the edges of the pan, leaving the middle empty. Reduce the heat to medium and add the remaining 1 1/2 teaspoons oil, then the onion and garlic to the center of the pan. Cook, stirring occasionally, until the vegetables start to soften, about 3 minutes. Add the chili powder, cumin and coriander and stir about 30 seconds. Add the tomato paste and 1 teaspoon salt and stir until the paste begins to darken in color, about 30 seconds. Then add the squash, tomatoes and 4 cups water, scraping the bottom of the pan to release any stuck bits. Bring to a simmer, adjust the heat and simmer, uncovered, until the chili has thickened and the squash is tender, 35 to 40 minutes.

Step 2

Stir the beans and chia seeds into the chili and heat through, about 5 minutes. Season with an additional 1/2 teaspoon salt and a few grinds of pepper, then taste the chili and stir in up to 2 tablespoons of vinegar. Spoon the chili into bowls and top each bowl with cilantro and a dollop of sour cream.