In a medium sized saucepan, heat the oil over medium high heat. When oil shimmers, add the diced ham and cook, stirring occasionally for 3-5 minutes or until the ham starts to crisp around the edges. Add the sofrito, and cook for 2 minutes more.
Stir in the Sazon seasoning, beans, and calabaza. If mixture appears too thick add a small amount of water, about 1/8 cup, to thin it out. Bring to a boil then reduce heat to a simmer, cover and cook for about 13-15 minutes, until calabaza is soft and can be pierced with a fork. Season with salt and pepper if needed.
Transfer beans to a serving bowl and garnish with chopped cilantro.