For the marinade, grind the garlic with the salt in a mortar.
Stir all ingredients or possibly in the hand mixer form and mix briefly.
Put the meat with the marinade in a freezer bag and put it in the refrigerator for one night. Turn from time to time to the other side.
Allow the meat to come to room temperature about 2 hours before grilling.
Prepare a broiler for indirect temperature.
Remove the meat from the marinade and dry it. Salt and season with pepper. Sear on each side directly over the coals for 2-3 min, then place in the center over the drip pan. Cover and grill for 15 min, then use a meat thermometer to measure internal heat. When it reads 52 °C (medium rare) (about 20 min), remove from broiler and rest loosely with aluminum foil for 5-15 min. Then slice against the grain into narrow slices.
Orange aioli and baguette or ciabatta. Super.