Boil eggs hard in about 10 minutes, rinse with cold water, peel and halve. In the meantime, clean and wash spring onions for the sauce and cut them into thin rings. Fry in hot oil.
Heat the fat and sweat the flour in it. Add stock and cream while stirring constantly and bring to the boil. Season to taste with salt, pepper, mustard and white wine. Serve mustard sauce and halved eggs sprinkled with spring onions, pink berries and some cress.