Seared Mackerel with Celeriac and Green Onion Purée

Ingredients

• Celeriac Purée

  • 4 cups (600 g) celeriac, peeled and cubed (about 1 large celeriac)
  • 2 garlic cloves, crushed
  • 2 green onions, chopped
  • 1 cup (30 g) flat-leaf parsley, roughly chopped
  • 1/3 cup (75 g) unsalted butter, softened

• Mackerel

  • 2 tbsp (30 ml) olive oil, plus more for serving
  • 1 1/2 lb (675 g) mackerel fillets, with skin, cut into 8 pieces
  • 4 green onions, halved lengthwise
  • 1/2 cup (40 g) kohlrabi or celeriac, peeled and finely diced
  • 1/2 cup (15 g) mini watercress or other microgreens