|For white sauce|
|Butter||1 Ounce (30 Gram)|
|Plain flour||2 Tablespoon|
|Milk||8 Fluid Ounce (1 Cup / 250 Milliliter)|
|French mustard||1 Tablespoon|
|White wine vinegar||3 Tablespoon|
|Freshly ground black pepper||To Taste|
|Olive oil||190 Milliliter (3/4 Cup)|
1. To make white sauce, melt butter in a saucepan, stir in flour (a). Cook over medium heat for 1 minute. Remove pan from heat and whisk in milk a little at a time (b) until well blended. Return to heat and cook, stirring constantly, until sauce boils and thickens. Remove from heat and season to taste with salt, pepper and nutmeg (c).
2. To make vinaigrette, place mustard in a bowl and whisk in the vinegar. Season to taste with pepper. Add oil a little at a time, whisking well until mixture thickens.