In a blender or food processor, puree onion, bell pepper, garlic, cilantro, and annatto powder. Set mixture aside.
Heat a large, heavy saucepan over medium heat. Pour in olive oil and saute ham with pureed mixture for 10 minutes, until browned. Mix in beans, potatoes, pumpkin, water, and salt. Reduce heat to low and simmer, stirring occasionally, for approximately 25 minutes, until mixture thickens and potatoes and pumpkin are tender.
