Put the semolina flour into a large mixing bowl along with the salt and instant yeast. Stir to combine.

Make a well in the middle and add 1 tbsp of the olive oil.

Add approximately 250 ml of water to the olive oil and stir to start bringing the ingredients together. Add more water, a little at a time, until a dough has formed: you may not need all the water, or you may need a little more. There should be no dry flour visible, but the dough should be firm and not sloppy.

Add 1 tsp of olive oil to the bowl and turn the dough in it so it's coated.

Cover the dough or place the whole thing in a large reusable polythene bag and leave to ferment at room temperature overnight.

Tip: If you want to slow fermentation down (e.g. if the room is warm or it's more convenient) do the fermentation in the fridge or leave at room temperature for a few hours then put in the fridge overnight.

The dough should have risen, spread out and be bubbly underneath. If not, leave a little longer. If it's been in the fridge, allow to come to room temperature before proceeding.

Dust a little semolina flour over your work surface, ideally covered with a silicone mat, and transfer the dough onto it. Fold over itself several times until smooth: add more semolina flour if needed to prevent sticking but try to use as little as possible.

Divide the dough into 6 pieces, using digital scales for accuracy, then shape each one into a ball. Now roll each ball back and forth into a smooth baguette shape approximately 18 cm long.

As each baguette is shaped, transfer to a board lined with baking paper and sprinkled with a little semolina flour. Tip: you may find it easier to move the baguettes later if you divide the baguettes between two boards.

Put the board/s in a large polythene bag or cover with oiled cling film or a wet tea towel. Set aside to prove somewhere warm for 30-45 minutes or until, when you press with a finger, the dough springs back slowly, leaving an impression. If the dough immediately springs back, leave longer.

Complete the next step while the baguettes are proving.

While the baguettes are proving

Preheat your oven to 240°C / 220° Fan / Gas 9 / 475° F with a shelf in the middle position. Place a large baking tray on it: if it can't fit all the baguettes, cook in batches.

Optional but recommended: place another shelf in the lowest position and put a deep metal roasting tin on it to preheat. Later, you will pour in cold water to create steam and help the bread rise. DO NOT USE GLASS: it could shatter when the cold water goes in.

When ready to bake, brush beaten egg all over the tops of the baguettes then sprinkle with sesame seeds.

Tip: If cooking in batches, don't top the second batch yet but put them somewhere cool so they don't overprove.

Remove the preheated baking tray from the oven and lift or slide the baguettes, still on their paper, onto the tray.

Put the tray back on the middle shelf and pour cold water from a jug into the hot roasting tin below. Immediately close the door and bake for 18 minutes.

After 18 minutes, reduce the temperature to 220°C / 200° Fan / Gas 7 / 425° F and remove the baking tray with baguettes.

Take the baguettes off the tray then return them to sit directly on the oven shelf.

Bake for another 2 - 4 minutes or until they sound hollow when tapped.

Tip: if baking a second batch, empty the deep tin of any water and put back in to stay hot, along with the baking tray.

Place the baguettes on a wire rack to cool before eating or storing.

Best eaten within 2 days or can be frozen. Can be refreshed by spritzing with water and heating in a low oven.