Cuban Black Beans and Rice Recipe

Name: Cuban Black Beans and Rice Recipe
Ingredients: 1 pound (450g) dried black beans, preferably turtle beans; 2 small ham hocks, about 1 1/4 pounds (get smoked ones, if you can); 1/2 cup extra-virgin olive oil; 3 1/2 cups finely chopped yellow onions; 1 1/2 cups chopped green bell peppers; 2 tablespoons finely minced garlic; 2 bay leaves; 1/4 teaspoon dried hot red pepper flakes; 3 tablespoons (45ml) white wine vinegar, plus more for white onions; Kosher salt and freshly ground black pepper; 2 large white onions, diced; 1 teaspoon sugar; 1/2 cup (120ml) dark rum; 1/4 teaspoon cayenne pepper; 1/4 teaspoon Tabasco sauce; Cooked long-grain white rice, for serving; Diced white onions seasoned with salt, a touch of sugar, and splash of vinegar, for serving (optional)