Walnut Tortellini with a Red Wine Mushroom Reduction

Ingredients (for 1 2 3 4 5 6 7 8 9 10 servings, Metric system SI US customary units )

Preparation

1. Preparations for the walnut filling (overnight or the day before)
   Put the walnuts in a small bowl and cover with at least 2 cm (¾ inch) of cold water. Put into the fridge for at least 8 hours or overnight.

2. For the cavolo nero crisps
   Preheat the oven to 180 °C (350 °F).
   If using large cavolo nero leaves, remove the stem from each leaf and trim the edges if necessary. Toss in a little oil and salt and place the kale on a baking tray (sheet). Bake in the oven for 10–15 minutes until dry and crisp but so that they have not yet taken on colour, then leave to cool and crisp up.

   The author uses cavolo nero, a special type of kale, which is also called Lacinato kale, or dinosaur kale.

   The cavolo nero chips can be stored in an airtight container for 3 days.

   A link to an alternative healthier version of this recipe and our motivation for creating this version can be found directly above the recipe photo.

3. For the mushroom stock
   Peel the onion and slice the onion and the carrot, celery and button mushrooms to a 3 mm (⅛ inch) thickness. Put all the ingredients, except the porcini mushrooms, into a covered saucepan and then pour in the water. Gently bring to a boil – it should take about 20 minutes to reach the boiling point.

   The author uses chestnut mushrooms, also called button mushrooms, which are immature, brown portobello mushrooms.

4. Once boiling, simmer very gently for 5 minutes, then remove from the heat. Immediately add the porcini mushrooms, stir to make sure they are submerged, then cover the top of the saucepan tightly with cling film (plastic wrap).
   Leave the stock to cool completely, then drain off the stock through a large sieve into a clean saucepan, discarding the vegetables.

5. Continue with the walnut filling
   Put the potatoes (including skins) for the filling into a small saucepan with 1 litre (4 cups) of water and 10 g (1¾ tsp) of salt and gently bring to a boil, covered with a lid. Simmer gently until the potatoes are soft, then drain.

6. While the potatoes are still hot, drain and rinse the walnuts. Put the walnuts into a blender and blend as finely as possible.
   Transfer the walnuts to a large bowl and add the warm potatoes (with their skins on) and the walnut oil. Mash well, then return to the blender and process until a smooth, creamy texture is achieved, adding a little water if necessary.

   Be careful not to add too much water because the dough should be fairly firm.

7. When smooth, transfer to a bowl and stir in the dill.
   Add a tiny pinch of cayenne pepper and check and adjust the seasoning.
   Transfer to a piping bag or small container and put in the fridge for at least 4 hours to firm up.

8. For the tortellini dough
   Heat the water. Grind the saffron to a fine powder using a pestle and mortar, then add the boiling water and leave to infuse for 20 minutes.
   Once the saffron is ready, put the semolina into a large bowl, add the olive oil and measure in the saffron water, adding cold water so that you again have 175 ml (¾ cup).

9. Using a spoon, bring the pasta mix together to form a rough dough, then transfer to a clean, dry work surface. Knead the dough for about 8 minutes, until smooth and supple.
   Wrap in cling film (plastic wrap) and put in the fridge for 30 minutes to rest, and ideally for longer as it will get firmer and easier to work with.

   The dough can be stored in the refrigerator for up to 3 days. Simply take it out of the refrigerator 30 minutes before using.

10. Shaping the tortellini
    Roll out the pasta using a pasta mashine. Use the second-to-last setting on the machine.
    Dust your work surface with semolina and place the dough on top. Using a cutter, cut rounds the same size as the width of your pasta sheet (up to 15 cm / 6 inches), ), continuing until you don’t have any dough left. 
    Line a baking tray (sheet) with cling film (plastic wrap) and lightly oil it.

    If you don’t have a pasta machine, you can also use a rolling pin.

11. Mix together 50 g (generous ⅓ cup) of plain (all-purpose) flour and 100 ml (scant ½ cup) of water into a paste in a small bowl and set aside. Pipe or spoon 1 small tablesoon of the filling into the centre of each round. Using your finger, spread the flour and water mix onto one half of each pasta round to act as a glue and then fold each round over into a half-moon shape, encapsulating the filling in a neat bulge in the middle.
    Using the soft pad of your thumb or finger, carefully but firmly press the pasta down firmly, pushing all the air out of the middle as you do so.

    Getting the right amount of filling is critical – too little and the pasta is disappointingly empty – too much, and it will burst open.

    You are trying to do 3 things: shape the filling into a neat bubble surrounded by pasta, eliminate any air pockets from the centre, and press the 2 halves of pasta together.

12. Once you have sealed all parcels, take the cutter you used earlier and, using a rolling motion, trim the rough edge from your half-moon shape.
    Now the tricky part. Dab one corner of the moon liberally with the flour paste and then, using your thumb to form a little crease in the filling bubble, fold both corners toward the middle sticking one to the other and pressing firmly.
    Place the finished tortellini on the oiled tray, cover with cling film (plastic wrap) and pop in the fridge for up to 8 hours until needed.

    Please see photos.

13. For the red wine reduction
    Bring the red wine to a boil in a wide-based saucepan, then simmer until it has reduced by three-quarters – you will need exactly 50 ml (scant ¼ cup), so measure to check and reduce further if needed.

14. Add the mushroom stock (from step 3) and bay leaf and bring to a boil, simmer again until it has reduced by two-thirds in volume – you will need exactly 350 ml (1½ cups) of reduced stock, so measure to check, and reduce further if necessary.

15. For the mushrooms
    Cut each king oyster mushroom “log” into 7 mm (⅓ inch) slices.
    Cut each button mushroom in half across the middle so that you have 2 flat discs, then cut these into 7 mm (⅓ inch) discs. Slice the shimeji mushrooms. 

16. Heat 1 tablespoon of olive oil in a small frying pan (skillet) and add the king oyster mushroom slices. Sprinkle with a little salt, brown one side to a golden brown and then flip and brown on the other side. Add the mushroom stock and reduce it down to make a glaze, then keep warm.

17. Heat the remaining olive oil in a frying pan (skillet) and add the button mushrooms, sprinkle with a little salt and fry for 2 minutes.
    Add the shimeji mushrooms and continue to cook until the liquid has released from the mushrooms and evaporated again.
    Add 4 tablespoons of the red wine reduction and cook to thicken slightly, then keep warm until needed.

18. Continue with the tortellini
    When ready to cook, put 4 litres (16 cups) of cold water and 40 g (2½ tbsp) of salt in a large covered saucepan and bring to a boil. Line a baking tray (sheet) with a kitchen (paper) towel and have a clean tea towel to keep the cooked tortellini warm.

19. Now cook your pasta. Turn the temperature down, so the water is at a gentle simmer.
    Gently place no more than 5 tortellini into the saucepan of simmering water and stir gently to prevent them from sticking to the base. You only need to cook for 1–2 minutes – they will float to the surface and the pasta will be firm but cooked – it must have bite.

20. As soon as they are done, carefully remove them, one at a time, using a slotted spoon and put on the lined baking tray (sheet). Cover with a tea towel to keep warm and prepare the next 5. Repeat until they are all cooked.

21. Serving
    Once the tortellini are all cooked, place 3–5 tortellini into each of 4 pasta bowls. Spoon the diced mushrooms over the top of each and then arrange the king oyster mushroom slices on top.
    Pour the mushroom reduction into the bottom of the bowl.
    Add a cavolo nero crisp to each bowl and serve immediately.