Heat olive oil in a large pot over medium heat.
Add chopped onion and sauté until translucent.
Stir in minced garlic and chopped bell pepper, cooking for another 3 minutes.
Add the pumpkin puree and vegetable broth, stirring well to combine.
Mix in black beans and kidney beans.
Sprinkle in chili powder and cumin, mixing thoroughly.
Season with salt and pepper to taste.
Bring the mixture to a simmer, then reduce heat to low.
Cover and let it cook for 20 minutes, stirring occasionally.
Serve hot, garnished with fresh herbs if desired.