1. Put the egg yolk, mustard, garlic, Worcestershire sauce and lemon juice into a blender and blend until smooth, whilst mixing pour in the olive oil slowly to complete the dressing, add salt and pepper to taste.

2. Tear the large Cos lettuce into pieces and place in a large salad bowl.

3. Add the dressing to taste, sprinkle over the parmesan cheese, chopped anchovy fillets, toasted croutons and serve.