MARY Berry will be one of the many celebrity chefs making a personal appearance at the Totally Food Show area of the CLA Game Fair being held in the grounds of Blenheim Palace, Woodstock, from July 25 to 27.

This recipe, which can be found in the revised edition of her Complete Cookbook (Dorling Kindersley), is so easy to make and so tasty (particularly if left to marinate overnight) that I often serve it at barbecues at this time of the year.

No doubt, Mary will be demonstrating dishes such as this at the game fair.

This recipe serves six.

You will need: 1lb (500g) skinless, boneless cooked chicken 3 spring onions, finely sliced For the sauce you will need: 5 tbspns sunflower oil 3 tbspns white wine vinegar 2 tsp Dijon mustard 2-3 tsp caster sugar, to taste 2 canned anchovy fillets, finely chopped 7fl oz (200ml) half-fat creme fraiche 1 tbspn chopped fresh tarragon 1 tbspn chopped parsley Salt and black pepper To serve: 2 perfectly ripe avocados Juice of half lemon 2 spring onions, trimmed and cut lengthwise into fine slices Small bunch watercress Method: Cut the chicken into bite-sized pieces and mix with spring onions in a bowl Whisk all the sauce ingredients together in another bowl, adding salt and pepper to taste Mix the sauce with the chicken, cover and marinate in the refrigerator for at least two hours, overnight if possible Just before serving, half, stone and peel the avocados, slice the flesh into half-inch (1cm) strips, and squeeze the lemon juice over them. Gently mix avocado into salad and serve on bed of watercress. Garnish with spring onions.