@vicgrinberg the terms «soup» kinda scares me a bit as a fundamentalist of the «frijoles Negros». Not sure what recipe you followed, but a sofrito is a must: some olive oil, finely chopped onion, when translucent add some minced garlic, when fragrant (about 30 to 90 seconds) you start adding some aromatic herbs like oregano, a bit of cumin, then some chopped bell peppers. From here you can go Cuban, add white wine and a bit of tomato sauce, add to your «soup» and let it cook until thickens.