Rinse the calamari rings thoroughly and place them in a colander to drain. Transfer them to a pan and pat them with kitchen towels until completely dry.
Prepare the batter: In a bowl, combine the all-purpose flour, corn flour, turmeric, salt, and black pepper. Mix well and pour in the beer. Stir with a whisk until the flour and corn flour are dissolved. Place the batter in the refrigerator for 30 minutes. This is the secret to achieving crispy batter.
Meanwhile, prepare the mayo dip: In a bowl, mix all the ingredients together and refrigerate the dip until needed.
Pour plenty of sunflower oil into a small saucepan and heat it well. Coat the calamari rings in flour and dip them into the batter. Fry the calamari in high heat until the batter turns golden brown and becomes crispy. Remove them from the pan and place them on a plate with kitchen towels to remove any excess oil. Serve the calamari with the mayo dip and sprinkle with freshly chopped parsley.