Heat oil in a deep pan over medium-high heat until it reaches around 350°F (175°C).
In a large bowl, mix flour, baking powder, salt, and pepper. Gradually whisk in the cold sparkling water until a smooth batter forms.
Pat the cod fillets dry and slice the onions into thick rings.
Dip the cod fillets and onion rings into the batter, ensuring an even coating.
Fry cod and onion rings in the hot oil for 4-5 minutes, or until golden and crispy.
Remove from oil and place on paper towels to drain excess oil.
Season with extra salt if desired and serve hot with your favorite dipping sauces.
Notes
For extra flavor, add smoked paprika or cayenne pepper to the batter.
Make sure the sparkling water is very cold for the crispiest results.
Fry in batches to avoid overcrowding the pan, which can make the batter soggy.
Store leftovers in the fridge and reheat in the oven to retain crispness.
Nutrition
Serving Size: 1 portionCalories: 420Sugar: 3gSodium: 540mgFat: 189gSaturated Fat: 3gUnsaturated Fat: 15gTrans Fat: 0gCarbohydrates: 42gFiber: 3gProtein: 25gCholesterol: 70mg
