Begin by making the dough. Form a well with the dry ingredients, and then add the egg, lemon juice, and oil into the centre; use a fork or your hand to combine. Knead vigorously for 10 minutes, and then rest for half an hour, sealed in cling wrap and away from direct sunlight and heat.
While the dough rests, warm the olive oil and the lemon and orange peel in a small pot, on very low heat for 10-15 minutes. Remove and allow to cool. Remove and retain the peel for plating or, if not using immediately, store it with the peel in the fridge for up to one week.
Next, prepare the filling by mixing together the ricotta, lemon zest, salt and pepper. Transfer it to a piping bag with a medium round tip (alternatively you can use a teaspoon to fill the pasta).
Roll the dough through a pasta machine, turning it through the thickest setting a few times (folding over itself in between passes), before incrementally stepping it through to a medium-thin thickness (on a 9-setting pasta machine, a setting of 6).
Use a round cookie cutter, of about 8cm diameter, to stamp the dough out into circles. Pipe a walnut-sized amount of filling into the centre of each circle.
To shape the pasta, fold the dough in half over the filling; press gently around the filling to seal. Then roll the filled centre of the pasta over so that the dough seam is now located underneath the pasta, off-centre. Pinch the ends to seal flat, vertically, then gently poke the top of each piece to form small dimples. Transfer the finished scarpinocc to lightly floured baking paper lined oven trays, and refrigerate uncovered for 1-3 days.
Cook the pasta in lightly salted boiling water until al dente. No raw dough should be visible when the pasta is cut into. Drain, and toss in the citrus oil, serving with freeze-dried sour cherries, the retained peel (if using it), pink peppercorns, and a crack of black pepper.