Prime Rib Roast

Ingredients

• 8 tablespoons butter unsalted, room temperature, 1/2 cup or 1 stick
• 2 teaspoons chili powder
• 1 teaspoon ground cumin
• 1 tablespoon chopped fresh thyme
• 1 tablespoon chopped fresh rosemary
• 3 cloves garlic minced
• 1 teaspoon salt or to taste
• 1 teaspoon pepper or to taste
• 5 pounds prime rib
• 2 onions medium, quartered
• 5 cloves garlic peeled
• 4 sprigs thyme
• 2 sprigs rosemary
• 1 cup dry red wine
• 1 cup beef broth low sodium
• 1 tablespoon cornstarch
• 2 tablespoons water