Heat one quart of water in a saucepan over medium heat. Add kosher salt and next 6 ingredients and stir until dissolved. Reduce heat to low and simmer brine 15 to 20 minutes to blend flavors. Transfer brine to a large container, add remaining 2 quarts of water, and allow to cool. Add ice.Place duck breast fillets in brine and refrigerate for 6 to 24 hours. Rinse fillets with cold water, pat dry, and rub with a thin coating of olive oil.Place fillets in a 170F smoker for 1 ½ to 2 hours or until internal temp reaches 135F (for medium rare).Slice smoked fillets thinly and serve with a fruit, cheese, and your favorite dipping sauce, or serve them in soft rolls with mustard and mayonnaise. Use smoked duck as you would any other smoked meat.