Combine pasta ingredients in a food processor and rest the dough for one hour.
Salt the diced apple and cucumber, wait 30 minutes, then squeeze out excess liquid.
Mix crab, lemon zest, chives, apple, and cucumber in a bowl and refrigerate.
Reduce apple juice in a pan to a syrup, then whisk in rapeseed oil, nigella seeds, and lemon juice.
Roll the pasta dough through a machine until thin and smooth.
Cut the pasta into forty 15cm squares.
Place a tablespoon of crab filling onto the center of 20 pasta squares.
Brush edges with water, top with remaining squares, seal tightly, and cut with an 8.5cm round cutter.
Brush spring onions with oil and char in a dry frying pan for a few minutes.
Boil ravioli in salted water for a few minutes, then drizzle with olive oil and sea salt.
Serve ravioli in bowls topped with charred spring onions and apple dressing.