Spinach potato soup with savoury egg custard

Savoury egg custard

• 4 eggs
• 100 g whole milk
• ½ tsp salt
• 1 - 2 pinches ground nutmeg

Spinach potato soup

• 80 g onions cut in halves
• 20 g oil
• 40 g celeriac
• 100 g carrots cut in pieces (2 cm)
• 200 - 250 g potatoes cut in pieces (2 cm)
• 80 g leeks cut in slices (1 cm)
• 800 g water
• 1 heaped tsp vegetable stock paste, homemade
  or 1 vegetable stock cube (for 0.5 l)
• ¼ tsp ground nutmeg
• 1 tsp salt plus extra to taste
• ¼ tsp ground pepper plus extra to taste
• 250 g fresh spinach leaves
  or 250 g frozen spinach leaves defrosted
• 80 g cream 30% fat