Heat the olive oil in a large heavy-bottomed pot over medium heat. Add the chopped onion and sauté until it becomes translucent and just begins to take on a golden edge (about 5 minutes).
Add the minced garlic and stir for about 30 seconds until fragrant—your kitchen should smell aromatic with a hint of sweet onion and garlic.
Increase the heat to medium-high, add the ground meat and break it up with a wooden spoon. Cook until browned and no longer pink, about 8 minutes. As it browns, you’ll hear a light sizzle and see little golden bits forming at the bottom.
Stir in the pumpkin puree, diced tomatoes (with their juice), tomato paste, drained black beans, sweet corn, and broth. Mix everything until the pumpkin has melted into the tomato base, forming a rich orange-red stew.
Sprinkle in the smoked paprika, cumin, chili powder, cinnamon, and season generously with salt and pepper. Stir until the spices are fully enveloped in the chili—see the swirl of pumpkin and tomato turning into a deeper hue.
Bring the mixture to a gentle boil, then reduce heat to low. Cover the pot and simmer for 30 minutes, stirring occasionally. During this time the flavors meld, the pumpkin rounds out the acidity of the tomatoes, and the chili thickens.
Remove the lid and let the chili simmer uncovered for another 10-15 minutes, until it reaches your preferred consistency (slightly thick yet spoonable). Adjust seasoning if needed.
Serve hot in bowls and top with your choice of sour cream or yogurt, cheddar, fresh cilantro, and jalapeño slices for a pop of color and spice.
