Mix the flour in a bowl for about 2 minutes.
Add cold beer from the refrigerator.
Whisk the mixture for about 3/4 minutes, until the batter is smooth.
Immediately dip the perch fillets into the batter without superposing them.
Drain the excess batter.
Carefully lower each fillet into the hot oil. (160°)
Turn the fillets from time to time.
When the batter is crisp and golden, remove the fillets from the oil and dry them on kitchen paper.
Place the chips next to the fish fillets, salt and serve hot.