Slimming World Syn Free Mayo:
6 tbsp very low fat natural fromage frais
2 tbsp white wine vinegar
2 tsp granulated artificial sweetener
1 tsp mustard powder
1 tsp water
To make the mayonnaise, mix together the fromage frais, white wine vinegar and artificial sweetener. Blend the mustard powder with the water and stir into the dressing. Season with the salt and pepper
There is also a French Dressing you can buy which is syn free but I think it is made by Kraft but you would need to double check.