How to Make It
In a large nonreactive pot, mix the water with the soy sauce, maple syrup and salt, stirring to dissolve the salt. Add the pork rib roasts and refrigerate for 2 hours.
In a large saucepan, mix the white wine with the vinegar, soy sauce, maple syrup and honey. Add the star anise, cloves, cinnamon sticks, fennel seeds, peppercorns and cumin seeds and bring to a boil. Cook over moderately high heat until reduced to 2 cups, about 25 minutes. Remove from the heat. Add the mint sprigs, cover and let stand for 30 minutes.
Strain the spice broth into a saucepan and bring to a simmer over moderately high heat. Whisk the cornstarch mixture, then whisk it into the broth and boil, whisking, until the broth is thickened, 1 minute. Remove from the heat; season with salt.
Light a grill. Preheat the oven to 350°. Remove the pork from the brine and pat dry. Grill over medium heat, turning several times, until lightly charred all over, about 15 minutes. Transfer the pork to a large rimmed baking sheet and roast for about 50 minutes, until an instant-read thermometer registers 150° when inserted into the thickest part of the meat. Transfer the pork to a carving board to rest for 10 minutes.
In a large, deep skillet, heat the olive oil. Add the onions, garlic and chile, cover and cook over low heat, stirring occasionally, until the onions are softened but not browned, about 25 minutes. Season with salt and pepper.
Bring a large saucepan of salted water to a boil. Add the green beans and cook until crisp-tender, about 3 minutes. Drain and pat dry. Stir the green beans into the onions. Cover and cook over moderate heat until warmed through.
Reheat the spice broth. Transfer the green beans and onions to a platter. Using a sharp carving knife, slice the roasts from the racks, using the bones as a guide. Carve the deboned roasts 1 inch thick and arrange on top of the onions. Pour the spice broth over the pork and serve right away.