Preheat the oven to 220°C (425°F) and place a 12-hole muffin tin or a larger tin in the oven to heat.
Sift the flour and salt into a mixing bowl to remove lumps.
Break the eggs into the flour and whisk briefly to form a thick paste.
Gradually pour in the milk while whisking until the batter is smooth and lump-free.
Add 1–2 tbsp water if desired for a lighter batter; whisk until glossy and well blended.
Strain the batter if needed, cover and rest at room temperature for 20–30 minutes.
When the tin is smoking-hot, add about 1/2–1 tbsp hot fat into each well and return to the oven until the fat shimmers.
Give the batter a final whisk, remove the tin, and quickly pour batter into each well to two-thirds full.
Return the tin to the oven immediately and bake undisturbed at 220°C (425°F) for 20–25 minutes until risen and golden.
For extra crispness, increase heat to 230°C (450°F) for the final 2–3 minutes, then remove and serve immediately.