1. For the marinade, whisk the marinade ingredients together in a bowl.
2. Stir in the sesame oil.
3. Using cocktail sticks pin the bottom of the meat to creating a round shape (quicker than to truss with a roasting string). If you have a nicely round cut you may not need to do this.
4. Place the meat in a freezer bag and pour the two thirds of marinade over it, gently rubbing the meat. Marinate in the fridge for at least 2 hours.
5. Preheat the oven to 180°C. Shake off the marinade juice from the meat and pat dry it gently. Rest it for 5 minutes to come to room temperature.
6. Heat a non-stick frying pan or flat griddle until hot and sear/seal it for 1½ minutes each side.
7. Place on a baking tray, drizzled with oil and roast for 5-8 minutes for medium-rare.
8. Remove, place on a board and cover with foil allowing to rest for 10 minutes. Keeping the juices in the pan.
9. Heat the butter over high heat in a large frying pan and sauté the garlic and ginger. Add the calamari and cook for 2 minutes until the legs curl up and cooked. Season with salt and pepper.
10. Remove from heat and stir in the coriander and squeeze of a lemon.
11. Remove calamari to plate and cover to keep warm.
12. To make a sauce, into the calamari pan –add the meat juices. Add the remaining marinade and cook for 8 minutes.
13. Pour in the stock and simmer until slightly reduced.
14. Grate in 1 teaspoon more ginger and strain though a sieve to serving jug.
15. Carve the fillet and arrange on a board, put the calamari on the board, garnish with coriander, serve with the gravy alongside.