Codfish with rapini or spinach by Ágata - Riberalves

Ingredients

• 150 g deep-frozen fillet codfish Riberalves
• 2.5 dl of skimmed milk
• 40 g of flour
• 40 g of margarine
• 4 egg whites
• 2 egg yolks
• 1/2 lemon
• salt and pepper to taste (don't use too much salt)
• nutmeg to taste