Spaghetti with Citrus Sauce

For the noodles: stir together the flours, xanthan gum and salt.

Whisk together the eggs and oil.

Add the egg mixture to the flour mixture, mixing until a dough forms.

Sprinkle a surface with cornflour and turn out the dough. Knead for 5-7 minutes, until no longer sticky. Continue to add more cornflour, as needed.

Shape into a log; cut into 4 pieces and set 3 pieces aside.

Place one piece of dough on a floured surface, flatten and shape into a rectangle. Keep the remaining dough covered with cling film, to prevent it from drying out.

Push the piece of dough through the pasta roller on the widest setting. The dough will crumble as it comes out of the pasta machine. Patch the pieces together gently and push through again on the widest setting. Repeat until the dough comes out in one piece.

Fold the sheet into 3 pieces and roll through the widest setting. Repeat 3 times until you have a rough square shape, then start working it through the machine, taking it down one setting at a time, until the thinnest setting. This will produce a long, wide sheet of pasta.

You can also roll the dough by hand using a rolling pin but you'll need to roll the pasta sheets really thinly.

Fold the dough and cut into strips. Hang to dry or place on a tray dusted with cornflour to dry for 10-15 minutes.

Repeat with the remaining dough.

For the pesto: Cut the lemons into wedges and discard the white pith and pips, then cut each wedge into smaller pieces.

Put into a food processor with the garlic and blend until the lemons begin to break down.

Add the walnuts and continue to blend until fairly smooth, but still slightly chunk. Drizzle in the oil and add salt and pepper to taste.

Cook the noodles in a pan of salted boiling water and cook for 2-5 minutes until just tender.

Drain in a colander and rinse with fresh boiling water to remove the excess starch.