Using a sharp knife, score the steak on both sides in a "plaid" fashion (this keeps the steak from curling up while under heat)
Squeeze fresh lemon juice over steak (both sides); lightly season with salt and pepper; allow to sit for 25 minutes
Meanwhile, 1 tablespoon oil in a skillet on medium heat
Add tomatoes, garlic and basil to tomatoes; allow tomatoes to cook until juice has reduced. Turn heat to simmer and cook the calamari steak.
Cooking Calamari Steak
Heat 1 tablespoon oil in a skillet on medium-to-medium high heat; Place steak in hot oil and do not move it for 3 minutes. (If it starts to curl, just use a potato masher to press down on it.)
Flip calamari after 3 minutes and cook on the other side
Cut steak into bite sized pieces and serve with a dollop of stewed tomatoes.
Notes
Calamari will take on the flavor of whatever it is marinated...if you want a spicy calamari, try cayenne pepper or Tabasco sauce.
If you prefer a beefy flavor, try marinating it in beef broth.