Heat vegetable oil in a Dutch oven or large pot over medium-high heat. Add beef and brown until no longer pink, breaking the beef up with a wooden spoon. Transfer beef to a bowl, leaving the grease behind in the pan.
Sauté onion and sweet pepper in beef drippings over medium-high heat until tender, about 3-5 minutes. Add garlic, chili powder, cumin, paprika, and tomato paste and cook 1 additional minute until fragrant.
Add browned beef, diced tomatoes, beans, pumpkin, and beef broth to pot and bring to a simmer over medium-high heat. Reduce heat to medium-low, cover pot, and allow to simmer 10-15 minutes, stirring occasionally.
Season chili with salt and pepper to taste and serve warm with optional toppings. Enjoy!