How to Make It
Preheat the oven to 300°. In a blender, combine the mango chunks with the sugar, tamarind paste, Worcestershire sauce, soy sauce and crushed red pepper and puree until smooth.
In a small saucepan, heat the vegetable oil until shimmering. Add the garlic and cook over moderate heat until fragrant, about 1 minute. Add the mango puree, season with salt and pepper and bring to a simmer. Cook over low heat until slightly thickened, about 5 minutes.
In a large ovenproof skillet, heat the olive oil until shimmering. Season the pork roast with salt and pepper. Add the roast to the skillet and cook over high heat, turning occasionally with tongs, until browned all over, about 7 minutes.
Transfer the skillet to the oven and roast the pork for about 45 minutes, until an instant-read thermometer inserted in the thickest part registers 130°. Brush the mango glaze all over the roast, turning to coat it evenly. Continue to roast the pork until an instant-read thermometer inserted in the center registers 135°, about 5 minutes longer.
Light the broiler. Brush some of the mango glaze and pan drippings over the pork and broil 8 inches from the heat for 5 minutes or until the glaze is slightly sticky and golden. Transfer the roast to a cutting board and let rest for 15 minutes.
Meanwhile, pour off the fat from the skillet and set the skillet over moderately high heat. Add the wine and cook, scraping up any browned bits. Transfer to a small saucepan and simmer the jus until reduced by half, about 5 minutes. Add the chicken stock and simmer until slightly reduced, about 3 minutes longer. Season the jus with salt and pepper.
Discard the strings from the roast and slice 1/3 inch thick. Serve with the jus.