Mix the flours together, setting half aside and forming a well out of the remainder. Drop the spinach, half a teaspoon of olive oil, and half of the egg into the centre of the well, and bring together into a ball. For a more vibrant and consistent colour, blitz in a food processor for one minute.
Knead vigorously for 10 minutes, then cover in cling wrap and set aside to rest for 30 minutes, away from heat and direct sunlight.
Similarly, prepare a well with the remaining flour, mixing in the other half a teaspoon of oil, the remaining egg, and two tablespoons of water into the centre. Knead for 10 minutes, and then cover and rest for 30 minutes.
While the dough is resting, sauté the red cabbage, onion, garlic, and peppercorns in one tablespoon of olive oil, over medium heat for 10 minutes, stirring regularly. Once the onion begins to soften and turn translucent, add in the stock, parsley, bay leaves, and salt, and simmer at low-medium heat for a further 15-20 minutes. Remove from the heat and strain out the broth. We like to retain the cabbage and serve it as a side, tossed with some blanched greens, olive oil, crumbled feta, and lemon juice.
Next, prepare the filling by blanching the asparagus in boiling water for 2-3 minutes. Set aside the tips, and then blend the stalks with the mascarpone, breadcrumbs, and salt. Note that you can retain the asparagus cooking water to later cook the pasta in. Transfer the blended filling to a piping bag fitted with a medium round tip.
Once the dough has rested, and working with one ball at a time, roll it through the pasta machine at the thickest setting a few times, folding each sheet over itself in between passes. Then gradually step them through to a medium-thin thickness (5 on our 9-thickness machine).
To laminate, lay one sheet out flat on a lightly floured surface, spritz the exposed side lightly with water, and then lay the second sheet on top, smoothing out any air bubbles with your hand as you go. Roll back through the machine at a thicker setting (3 on our machine).
Spritz the surface of the laminated sheet with water, and then carefully roll up into a tight log, short-end to short-end. Use a sharp knife to cut across the pasta, forming spiralled discs of around 3-4mm thickness. For this original recipe of 300g flour, form approximately 28 discs.
Cover any pasta that you’re not using to prevent it drying out, and then roll each disc through the pasta machine to a medium-thin thickness (5 on a 9-thickness machine). Squeeze a grape-sized amount of filling into the centre of each piece, and fold in half, using your fingers to press down around the filling and seal the pasta. Cut a semicircle around the filling, with the dough fold on the flat side, and then bring the corners around the filling to meet. Pinch gently, slightly behind where the points meet, to complete the shape, and transfer to lightly-floured baking paper lined oven trays.
Drop the cappellacci into lightly salted boiling water, and cook until al dente (firm, but no white showing when you cut across the dough). This could take more than 10 minutes depending on the thickness of the pasta. Drain, and serve in the broth with the asparagus tips, crumbled feta, zucchini ribbons, pistachios, and micro-herbs.