Rub chops with oil, season, and sear 2–3 min per side; set aside.
Toss potatoes, carrots, fennel, garlic, and rosemary with oil, salt, and pepper; roast 25 min.
Add chops among vegetables; roast until 140°F and veggies are tender (10–15 min).
Whisk parsley, shallot, vinegar, mustard, sugar, salt, and pepper; whisk in oil.
Rest meat 5 min; drizzle with vinaigrette and serve.