Preheat the oven to 140°C (gas 1).
Clean the squid, pull out the head and tentacles with the giblets.
Cut off the heads below the eyes and discard, set the tentacles aside.
Rinse the mantles, pull out the transparent fish bone, and cut the mantles into rings. Scoop out shrimp, leaving tails intact. Clean squid: cut open the head and remove the innards. Cut out the eyes and hard jaw.
Rinse octopuses. If they are fairly large, cut in half or quarters. For the sauce, heat the oil in a skillet.
Saute all ingredients over low heat for 1 minute, until garlic is al dente but not brown.
Serve warm or chilled. For the dough: sift the flour and ¼ tsp salt into a bowl. With a wooden spoon, add the oil
Stir in, then slowly add 315 ml of warm water. If the dough becomes runny, whisk until smooth and thick.
Beat the egg whites until stiff and fold them in. In a deep fryer or deep pan, heat oil to about 190°C (until a bread cube turns golden brown in 10 seconds). Pat the seafood dry with kitchen paper to make the batter stick. Process one type at a time. First dip them in the batter, let them drip off a bit. Then carefully put them into the oil. Fry for 2-3 minutes, depending on size. Drain on paper towels, keep warm in the oven.
Do not put them on top of each other! Now deep-fry the next seafood.
Garnish all seafood with lemon and parsley and serve immediately with the sauce.