Saute the onions, garlic, scotch bonnett peppers and spices and cook, stirring occasionally, until very soft, about 10 minutes. Do not brown.
Transfer the cooked onion mixture to a blender and add the black beans, salt, lime juice, water and spices. Blend until smooth. If the blender is straining, add water if needed. If the dip is too thick, add a little water.
Taste and adjust seasoning, then serve warm or cold at room temperature. 2 tbsps is a serving.