In a small mixing bowl, mix together the ¾ cup of flour, beer, and 2 teaspoons of oil. Cover and place in the fridge for minimum 30 minutes, up to 2 hours.
Place potato strips in a large bowl of cold water.
Pour at least 2 inches of oil in a deep heavy saucepan, heat over medium heat to 160° C (320° F).
Drain and dry potatoes, fry in batches for 3 minutes or until slightly softened but not browned. Drain on a paper towel lined plate.
Remove flour mixture from fridge. Stir the egg yolk into the mixture.
Add the egg white to a medium size mixing bowl and beat with an electric mixer on medium high speed until soft peaks form.
Fold the egg white into the flour mixture.
Preheat your oven to 95° C (200° F) and heat the oil to 185° C (365° F). Dust fish pieces with flour, dip pieces in batter, shaking off excess.
Carefully lower fish pieces into the hot oil. Work in batches and do not crowd the pan. Fry fish 4-6 minutes or until batter is browned and fish is cooked through, turning once. Allow oil to heat back up between batches. Drain cooked fish on paper towels and keep warm in the oven.
After the fish is all cooked, cook the potatoes in batches, 5 minutes or until browned and crisp. Drain on a paper towel lined plate and sprinkle with salt to taste.
Serve fish and chips together with tartar sauce and lemon wedges on the side, garnish with parley. Enjoy.