Grilled Pork Loin with Olive-Caper Relish and Avocado Butter

8 6-ounce portions boneless pork loinOlive-caper relish2 tablespoons, plus 4 teaspoons olive oil, divided2 cups thinly sliced red onion2 tablespoons sherry vinegar2 tablespoons dark brown sugar 1/2 cup chopped, pitted black and green olives 1/4 cup capers2 tablespoons cream sherry2 tablespoons lime juice2 tablespoons minced thyme leaves2 teaspoons minced rosemary2 tablespoons olive oilSalt and pepper to tasteAvocado butter4 teaspoons olive oil 2/3 cup minced shallots 3/4 cup cream sherry2 2/3 cups chicken stock5 1/3 ounces unsalted butter, cut into 8 pieces1 1/2 ripe avocados, peeled and cut into sixthsFor the olive-caper relish: Heat the 4 teaspoons olive oil and sauté the red onions until tender and browned. Deglaze with sherry vinegar, breaking up any browned bits and stirring until vinegar evaporates. Add brown sugar and stir to caramelize onions. Scrape onions into bowl and let cool.Combine black olives, capers, cream cherry, lime juice, thyme, rosemary, 2 tablespoons olive oil and salt and pepper with onions and mix gently. Reserve at room temperature.For the avocado butter: Heat the olive oil in a saucepan and sauté the shallots until tender. Deglaze with cream sherry and add the chicken stock. Bring to a boil, reduce the heat and simmer until reduced by one-fourth. Strain and keep warm.For the plate: Season the pork portions with salt and pepper. Grill the pork loin slowly to medium-rare, let rest 5 minutes.For each portion: while pork is resting, bring 1 1/2 ounces strained chicken stock to a boil in a sauté pan and whisk in 1 piece of butter and 1/6th of an avocado. Whisk until thickened and emulsified and season with salt and pepper.Slice pork loin into 3 pieces and top with the olive-caper relish. Sauce the plate with the avocado butter.Serves eight.Nutrition values per serving: 697 calories, 56 g fat (20 g saturated), 13 g carbohydrates, 4 g fiber, 36 g protein, 150 mg cholesterol, 681 mg sodium.Chef Susan Goss, West Town Tavern, Chicago for Hass Avocados from Mexico