Beer-Glazed Beer Can Chicken - Rick Bayless

Ingredients

• 1 teaspoon fresh black pepper
• 1 tablespoon dried oregano, preferably Mexican
• 1/2 teaspoon fresh cumin
• 1 large (4 pound) whole chicken, preferably Kosher
• Salt
• 1 12-ounce can dark Mexican beer (divided use)
• 1 head garlic, sliced in half around the equator (divided use)
• 4 to 6 cups chopped root vegetables—think potatoes, carrots, onions and the like (3/4-inch pieces are good) (optional)
• 2 to 3 tablespoons vegetable or olive oil (optional)
• 1/2 teaspoon chile flakes
• 3 tablespoons (3/4 ounce) piloncillo (Mexican raw sugar) chopped, or brown sugar