1. Preheat oven to 160°C (325°F).
2. Take meat out 20–30 minutes before cooking and let stand until it reaches room temperature. Take the point of a knife and make shallow incisions in the fatty side of the meat every 5 mm (¼ lb.) across its width. Season generously with salt and pepper.
3. To make the sauce, squeeze the garlic head to extract the grilled garlic and crush each clove.
4. Combine grilled garlic, oil, Dijon mustard, maple syrup, lemon zest, and tarragon in a small bowl.
5. Add salt and pepper to taste.
6. Mix well and set aside.
7. Heat a grill pan or other large cast iron skillet on high.
8. Place loin in skillet and grill on both sides.
9. Transfer pork to a drip pan, fatty side up, and bake 20–25 minutes per 450 g (1 lb.), around 1 hour and 40 minutes total.
10. Take pork from oven and cover with aluminium foil.
11. Let stand for 5 minutes.
12. Cut loin diagonally in 1 cm (½ in.) slices.
13. Drizzle tarragon sauce over pork.
14. Serve with garlic accordion potatoes and grilled parsnip.

CHEF’S SECRET

To cook the pork to perfection, take it out of the oven before it reaches the desired temperature. Cover and let stand: the temperature will continue to increase by a few degrees. For slightly pink pork, insert a meat thermometer in the centre of the loin. The temperature must reach 70°C (160°F).

To make accordion potatoes, thinly slice potatoes along their width three quarters of the way through and insert thin slices of garlic with butter and fine herbs. Drizzle with a little olive oil. Bake at 200°C (400°F) for 40 minutes.