Cook pasta according to package directions. While pasta is cooking, cut cheese into 8 equal cubes and sprinkle with mastic. Stuff the calamari with a piece of cheese, repeating until all calamari is stuffed with cheese. Baste all calamari with olive oil and season with salt & pepper. Cook on a hot grill or in a hot skillet for about 2-3 minutes per side. Remove to plate and set aside.
In a large skillet on medium high heat, add remainder of olive oil and diced tomato and stir well. Season with salt and pepper add the spinach and sauté quickly. Toss in the pasta and mix well.
Plate the pasta and top with squid.
Serve and enjoy!