Prepare the cleaned squid by cutting down one side of each body tube and opening it out flat.
Using a sharp knife, lightly score the inside surface in a shallow crosshatch pattern. Take care not to cut all the way through the flesh.
In a bowl, combine the lemon zest, cumin, a pinch of sea salt, olive oil, and garlic paste.
Add the squid and gently rub the marinade over the bodies and tentacles until evenly coated.
Cover and refrigerate for at least 2 hours.
Remove the squid from the refrigerator shortly before cooking. Heat a grill pan, griddle, or outdoor grill until very hot.
Lift the squid from the marinade and allow excess oil to drip away.
Place the Grilled Squid with Lemon, Garlic and Cumin on the hot grill. Cook each side for no more than about 2 minutes, depending on thickness, until lightly charred and opaque.
Grill the tentacles alongside the squid, pressing them gently against the hot surface with a spatula if needed to encourage even contact.
Transfer the cooked squid immediately to a serving platter. Finish with fresh lemon juice, chopped coriander, and a small sprinkle of sea salt.
Serve immediately while warm and tender.