Definitely you do not want to miss this place during your stay in Havana.
cuba recipes .org - The Genuine Cuban Cuisine
Congri is a very popular Cuban dish consisting of rice and red beans. It is ubiquitous in the eastern part of Cuba, in fact, many people consider congri to be the "signature dish" of Oriente province. It is a very good dish!
In blender or food processor, purée onion and green pepper together (add a little water if needed). Set aside.
In Dutch oven heat the oil on medium-high heat. Add the salt pork and garlic cloves. Sauté until browned. Discard the garlic.
Add the onion/pepper mixture to the oil, stir and cook for 5 minutes. Add the tomato sauce and continue to cook, stirring occasionally, for another 5 minutes until the sauce is a deep, rich red. This mixture is called sofrito.
Stir in the rice, mixing it well. Add the beans, water and salt and stir. Cook on high heat, uncovered until water begins to boil. Adjust heat to low, cover and let simmer for about 20 minutes until rice is tender.