Sift flours and salt into a medium bowl. Whisk in egg, melted butter and ¾ cup milk until smooth. Cover bowl with plastic wrap and refrigerate for at least 30 minutes. For best results, leave overnight.

Combine tomatoes, 2 tbsp oil, 1/4 tsp salt and pepper in a bowl. Place tomatoes, cut side up, on a wire rack over a baking dish and roast at 100°C for about 1 hour, until tomatoes are semi-dried.

Remove batter from refrigerator and stir in remaining milk (or more if needed) so batter is at pouring consistency.

Heat a 20cm, non-stick pan over a medium flame. Add a little butter and melt evenly in pan, wiping away any excess. Hold pan away from flame and ladle in about 1/4 cup of batter. Quickly tilt pan to completely cover surface with a thin and even circle of batter, return pan to the heat, and cook for 1-2 minutes, until the edges are brown and the centre is dotted with air bubbles. Turn crêpe over and put a dab of softened butter on top. On one half place a slice of ham, some gruyère and 1 egg yolk. Continue to cook until yolk is just set, less than a minute. Transfer to a plate and fold into quarters. Repeat with remaining batter, making sure to add butter to the pan for each of the 8 crêpes.

These are best eaten straight away. Otherwise, keep in oven on a low heat until you've made the rest. Serve with leaves lightly dressed with the remaining oil and seasoning and the slow-cooked tomatoes.

HOT TIP

• The crepes are excellent served with ricotta and maple syrup (or good-quality honey) if you don't want to do the full ham and egg thing.