Heat the olive oil in a large pot or Dutch oven over medium-high heat. Add the lean ground beef and cook for 6–7 minutes, breaking it up with a wooden spoon, until browned all over. Drain off any excess fat.
Add the onion and cook for 4–5 minutes until softened, then stir in the garlic, chili powder, cumin, smoked paprika and cinnamon and cook for 1 minute until fragrant.
Stir in the pumpkin puree, diced tomatoes, black beans and beef broth. Season with salt and pepper and bring to a gentle simmer.
Reduce the heat to low, cover partially, and simmer for 35–40 minutes, stirring now and then, until thick and rich. Taste and adjust the salt and spices.
Ladle into bowls and top each serving with a spoonful of Greek yogurt and a sprinkle of fresh cilantro.
Notes
Use plain pumpkin puree, not pie filling. Simmer the full 35–40 minutes for the best flavour. Keeps 4 days refrigerated; freezes up to 3 months.
Keyword ground beef, high protein, one pot, pumpkin chili, thanksgiving