The amount of flour can vary according to the time and humidity in the air, so I always recommend starting with less flour and adding it when you have the perception of the yield. I prefer to use less flour rather than add water because it can make the dough stickier.
Ingredients for 4 people:
300 grams of buckwheat flour
100 grams of rice flour
2 tablespoons of extra virgin olive oil
10 grams of xanthan (available in organic shops)
for the pesto:
the leaves of a whole stalk of strictly organic celery (by stalk I mean the whole "plant")
a handful of hazelnuts
40 gr of Pecorino Cheese
50 of Grana Padano Cheese
The juice of half an organic orange
Extra virgin olive oil
Salt and pepper as required
Combine the flours in a bowl or on a pastry board; make a well in the middle of the mound of flour and pour the previously lightly beaten eggs; add the oil, xanthan gum and start kneading with your fingers bringing the flour towards the center and knead vigorously with your hands. Work the dough by adding a few tablespoons of water from time to time until the dough is smooth, homogeneous and easy to handle (generally it takes about ten minutes). Wrap in cling film and let it rest in a cool place for at least half an hour. After that, make 2/3 cm diameter sausages with your hands that you will cut to obtain ½ cm thick disks that you will press between the two molds of the special tool. Always keep water within reach and "moisten" the dough should it be dry
Pesto: wash the celery leaves, dry them very well and leave them for a few hours on a cloth covered with household paper to absorb excess moisture (the water causes it to blacken). Put the leaves, pistachios, almonds, orange juice, a pinch of salt in a blender and start blending adding the oil slowly. When the mixture begins to be "chopped" add the two cheeses alternating a handful of cheeses with the oil until the cheeses are finished and the sauce has reached the consistency of a cream.
While the pasta is cooking, put the pesto in a baking dish, dilute it with a little bit of cooking water and add the freshly drained pasta. Garnish with very coarsely chopped pistachios and a little chopped orange zest.