Place a large skillet over medium heat. Add the chorizo, breaking up until browned and cooked through, about 8 minutes.
While the chorizo cooks, scoop out some of the inside of the rolls. Mist or brush with oil and broil for 1-2 minutes, until toasted. Set aside while the beans cook.
Add 1 tablespoon of oil (or more depending on how much fat the chorizo rendered) and the beans with their liquid. Simmer until slightly thickened, mashing with a potato masher, fork, or the back of a wooden spoon. Keep in mind that the mixture will thicken more once the beans are smashed. Season with salt and pepper to taste.
To serve, add about half a cup of the bean mixture to the bottom of each roll. Top with cheese, guacamole, salsa and/or hot sauce, and sliced radishes. Serve immediately.
The bean mixture keeps well refrigerated and makes for excellent leftovers.