Heat a large pot over medium heat and brown the beef with the onion and garlic. Once browned add the sweet potatoes. I kept mine on the larger side as I didn't want them to get too mushy.
Add the diced tomatoes, pumpkin, and tomato paste. It's going to be thick so add at least 1 can of water. Then add the frozen spinach and mix in until it breaks up.
1 15 oz can of petite diced tomatoes, 1 small can tomato paste
Add the rest of the ingredients and cook over medium heat until it bubbles, then lower heat to simmer.
1 15 oz can pumpkin puree, ½ lb 8 oz frozen spinach (I used half a 1-pound bag), 3 tablespoon chili powder, 2 tablespoon cumin, 1 tablespoon unsweetened cocoa powder, 1 teaspoon cinnamon, ½ teaspoon ground red pepper, ½ teaspoon kosher salt
Let simmer at least an hour until the sweet potatoes soften.