Preheat the oven to 375°F. Score the fatty side of the duck breasts. Season duck on both sides with the Essence, salt and pepper and place in the refrigerator overnight. In a large, heavy skillet over high heat cook duck breasts skin side down until golden brown and crispy, about 6 minutes. Turn and sear the second side for 1 minute. Transfer the duck breasts to a pan. Remove all but 2 tablespoons of the duck fat from the skillet. Add the shallots and sauté for 1 minute. Add the garlic and sauté for 30 seconds. Add the orange juice and tea. Bring to a boil and reduce by 50% in volume. Add the stock; reduce the heat to medium-low, and simmer until reduced by 50% in volume, about 15 minutes. Place the duck breasts in the oven to heat through and finish cooking while the final sauce is being assembled, about 5 minutes for medium-rare. Strain the sauce through a fine mesh strainer, pressing on the solids with the back of a spoon to extract all the liquid. Return the sauce to the pan. Add the marmalade and rosemary, and stir to combine. Taste and adjust the seasoning as necessary. Whisk in the butter and remove from the heat. Remove the duck breasts from the oven and divide among 4 serving plates. Spoon the sauce over the duck and serve.
Makes 4 servings.