Rinse all seafood under cold running water, then spread on a double layer of paper towels. Pat completely dry - press firmly. Any surface moisture will cause dangerous oil splatter and a soggy crust.

Check squid rings are no more than 1 cm thick. If any whole fish are over 12 cm, score two shallow diagonal cuts on each side to help them cook through evenly.

Pour semolina into a large shallow bowl and mix in 1 tsp of the sea salt. Set a wire rack over a sheet pan near the stove.

Pour sunflower oil into the heavy-bottomed saucepan to a depth of at least 6 cm. Clip the thermometer to the side. Heat over medium-high heat until the oil reaches 183 C (360 F). This takes 8-10 minutes.

Working with the squid first (it tolerates slightly lower oil temp), drop rings and tentacles into the semolina in batches of about 100 g. Toss to coat, then lift out and shake in your cupped hands to drop all loose semolina back into the bowl.

Lower coated squid carefully into the oil using a spider strainer. Fry for 2 minutes until pale gold and just starting to color at the edges. Remove to the wire rack and do not stack.

Bring oil back to 183 C. Dredge shrimp in semolina in batches of 150 g, shake off excess, and fry for 2-3 minutes until the shells are crisp and shells turn orange-pink. Transfer to the wire rack.

Bring oil back to 183 C. Dredge whole fish in semolina, shake firmly to remove loose coating. Fry in a single layer - no more than 5-6 small fish at a time - for 3-4 minutes, turning once with the spider strainer, until golden brown and the tails are visibly crisp.

Remove to the wire rack. Repeat with remaining fish, letting oil return to temperature between each batch.

The moment each batch comes out of the oil, season immediately with a pinch of fine salt while still hot - salt won't stick once the crust cools.

Arrange all the fried seafood on a large plate or directly on food-grade paper. Scatter parsley if using and serve at once with lemon wedges.