Method

• Bring a pot of water to a boil
• Add 4 cavolo nero leaves and the silverbeet leaves and cook until soft, about 5 minutes
• With remaining leaves finely slice and set aside
• Rinse quickly under cold water
• Put cooked leaves in a blender or food processor and add just enough water to allow machine to puree until smooth
• Set aside
• Heat the stock in a medium saucepan over low heat
• Put oil and 1 tablespoon butter in a large, deep saucepan over medium heat
• When it is hot, add onion, celery and sliced silverbeet leaves, stirring occasionally until soft but not yet brown, 3 to 5 minutes
• Add rice and cook, stirring occasionally, until it is glossy, about 2 to 3 minutes
• Add white wine, stir, and let liquid bubble away
• Add a large pinch of salt
• Add warmed stock, 1/2 cup or so at a time, stirring constantly
• Each time stock has just about evaporated, add more
• After about 15 minutes, add cavolo nero leaves, and a couple of spoons of the puree, continuing to add stock when necessary
• Taste the rice as you go, you want it to be tender but with a bit of crunch; it could take as long as 25 minutes total to reach this stage
• When it does, stir in ½ of the leaf puree
• Remove saucepan from heat, add remaining butter and stir briskly
• Add Parmesan and stir briskly, then taste and adjust seasoning
• Risotto should be slightly soupy
• Serve immediately