Broccoli and kale soup with lemon creme fraiche

Ingredients

• Broccoli and kale soup
• 200 gram kale leaves, stems removed, chopped coarsely
• 1 1/2 tablespoon olive oil
• 1 large brown onion (200g), chopped finely
• 3 clove garlic, chopped finely
• 1.5 litre (6 cups) good-quality vegetable stock
• 650 gram sebago potatoes, chopped
• 450 gram broccoli, cut into florets, stems sliced thinly
• 1 cup loosely packed fresh flat-leaf parsley leaves
• Lemon creme fraiche
• 1 cup (240g) creme fraiche
• 1 tablespoon finely grated lemon rind
• shredded lemon rind, to serve