Clean squid: Remove ink and heads and any hard plastic-line bones. Transfer squid to a medium bowl and squeeze the juice of the lemon; marinate for 20-30 minutes.

In a medium pan, saute garlic and onion rings (for 3 minutes) until softened. Add squid to pan and fry for 20-30 minutes. Pour the calamansi juice, soy sauce and water. Season with salt and pepper. Let it boil and simmer for 10 to 15 minutes or until squid is fully cooked and tender.