Make the sauce first. Cook all the vegetables except the beans in the olive oil until they're just barely tender. Add the beans, salt, and enough water to cover by about an inch. Simmer until the beans are tender--about two hours.
When the beans are tender enough to squash with thumb and forefinger, add the sherry. Then puree the mixture in a blender. Add a little water if necessary to give the beans a sauce consistency. Keep warm.
Now make the stuffing. In a heavy skillet over medium heat, cook the butter until bubbling and add shallots, garlic, mirliton, squash, and Creole seasoning. Cook until the vegetables soften. Cool to lukewarm, then add the cheese.
Place one-sixth of the stuffing atop a pounded slice of the capretto. Roll it up and secure with a toothpick running in the same direction as the seam of the meat.
Combine the salt and pepper with the flour. Dust the goat meat with the seasoned flour.
Heat the olive oil in a heavy skillet until it shimmers. Sear the rolled-up goat slices, turning every minute or so until lightly browned.
Allow the rolls to cool for about five minutes. Slice the rolls on an angle into three or four slices.
Spoon about 1/4 cup of the black bean sauce onto warmed plates. Top with the capretto rolls. Garnish with the green onions, cilantro, and crumbled cheese.