Step 1

For sauce gribiche, combine cornichons, capers, mustard, olive oil, vinegar and herbs in a bowl and whisk to combine. Add eggs, season to taste and mix to combine; set aside.

Step 2

Sift flours, baking powder and bicarbonate of soda into a large bowl and mix to combine. Add buttermilk, oil and egg yolks; season and whisk until smooth. Squeeze any moisture from grated potato then add to the batter along with cheese; fold to combine.

Step 3

Whisk egg whites and a pinch of salt in the bowl of an electric mixer fitted with a whisk until stiff peaks form. Add egg white to flour mixture and gently fold to combine.

Step 4

Heat a waffle iron to medium heat and lightly brush with oil. Pour about ¼ cup batter into each section of the iron (depending on its size) and cook waffles until golden brown (4-5 minutes). Repeat with remaining batter.

Step 5

Serve waffles with sauce gribiche, rocket and cracked black pepper.