Start by dicing the onion finely and mincing the garlic to prepare flavorful aromatics.
Next, in a skillet over medium heat, brown the ground meat until it's no longer pink and begins to develop a light golden crust, about 5-7 minutes. Break it apart as it cooks for even browning.
Transfer the cooked meat to your slow cooker, then add the diced onions, minced garlic, drained beans, diced tomatoes with their juice, and pumpkin puree. Stir everything together to combine well.
Sprinkle in the chili powder and cumin, and season with salt and pepper to your taste. Give everything a good stir so the spices are evenly distributed throughout the mixture.
Cover the slow cooker with the lid and cook on low for about 4 to 6 hours, until the flavors meld, the chili thickens, and it becomes bubbling gently with a rich aroma filling the air.
Once done, stir the chili gently to ensure all ingredients are well combined. Taste and adjust seasoning if needed.
Serve the pumpkin chili hot, with your favorite toppings like sour cream, shredded cheese, or fresh cilantro for added flavor and presentation.