In saucepan of boiling salted water, cook potatoes and 4 of the garlic cloves until potatoes are tender, about 15 minutes. Reserving ½ cup of the cooking liquid, drain; transfer potatoes and garlic to large bowl.
Add reserved cooking liquid, oil and half each of the pepper and salt; smash with potato masher until smooth with a few chunks remaining. Stir in chives. Keep warm.
Mince remaining garlic. Combine garlic, rosemary, mustard, and remaining pepper and salt. Rub all over chops. Place on greased grill over medium-high heat; close lid and grill, turning once, until desired doneness, about 8 minutes for medium-rare. Serve with potatoes and Château des Charmes 2016 Pinot Noir, Estate Grown & Bottled.