2 tablespoons olive oil, plus more for drizzling
1 small onion, thinly sliced
4 garlic cloves, peeled
2 (15.5-ounce) cans butter beans, rinsed
½ cup canned chopped tomatoes
2 sprigs thyme
Kosher salt and freshly ground black pepper
1 cup plus tablespoon water
1 prepared confit duck leg (5 ounces)
4 thick slices airy country bread
Fresh Italian parsley leaves, chopped, for garnish
Heat a medium (10-inch) skillet over medium-high heat. Add 1 tablespoon of the oil, the onions, and 3 of the garlic cloves. Cook, stirring occasionally, for about 5 minutes, until the onions and garlic start to color. Reduce the heat to medium-low and continue cooking, stirring occasionally, for 25 minutes, or until caramelized.
Add the beans, tomatoes, thyme, the remaining 1 tablespoon oil, ¼ teaspoon salt, and 1 cup of the water. Turn the heat up to medium- high and bring to a simmer. Smash about one-eighth of the beans against the side of the pan with a fork to thicken the mixture. Cook until thickened, about 5 minutes.
Transfer to a bowl, discard the thyme, and smash the garlic cloves. Season with salt and pepper, stir well, and cover with foil to keep warm.
Preheat the broiler.
Rinse out the pan and return it to the stovetop. Add the confit duck leg skin-side down to the cold pan. Turn the heat to medium-low, add the remaining 1 tablespoon water, cover the pan, and cook for 10 minutes (when the skin softens, scrape it off the duck leg and continue cooking alongside it; this will become the crackling). Remove the lid, turn the duck leg, and continue cooking until the leg is warmed through and starting to crisp up, turning as needed.
Continue cooking the duck skin (as if it were a slice of bacon) until nice and crisp, keeping in mind that it will crisp more as it cools (as if it were a slice of bacon), about 3 minutes longer. Drain on a paper towel.
Toast the bread on both sides under the broiler until it is crisp on the outside and still soft inside. Rub each slice generously with the remaining garlic clove and top each slice with about ½ cup of the beans. Shred the duck meat and divide it evenly among the toasts. Season with salt and pepper, drizzle with more oil, if desired, and crumble the crackling over the top. Sprinkle with the parsley and serve.