Heat the oven to 450 F.

Place the pork roast on a rack in a roasting pan or large skillet.

In a cup or small bowl, combine the sage, thyme, garlic, olive oil, 1 teaspoon kosher salt, and 1/2 teaspoon ground black pepper. Rub the roast all over with the seasoning mixture.

Roast the pork at the high temperature of 450 F for 10 minutes. Reduce the heat to 325 F and continue roasting for about 1 1/2 hours, or until the pork registers 145 F on a meat thermometer or oven probe inserted into the center of the thickest part of the roast, not touching bone. Note, 145 F is the minimum safe temperature for pork. The temperature will rise between 5 and 10 degrees on resting. Roast the pork to 155 F if you prefer well-done pork.

Remove the roast to a platter and tent it with foil.

Meanwhile, make the Madeira pan sauce. Remove all but 2 tablespoons of pan drippings from the roasting pan or skillet. Place the pan over medium heat and add the shallots. Saute the minced shallots in the pan drippings for about 2 minutes, or until tender. Add the Madeira wine and bring to a boil. Boil for about 1 minute. Add the chicken stock and bring to a boil. Boil over medium heat, stirring frequently, for about 5 to 7 minutes, or until the sauce is reduced by about one-third.

Combine the flour and water and whisk until smooth; stir into the sauce and continue cooking until thickened. Add 1 tablespoon of butter and stir until melted.

Taste and add salt and pepper, as needed.

Serve the roast with the Madeira sauce.