Given the task definition and input, reply with output. In this task, you will be presented with the directions of a recipe separated by "," and have to fill in the "___" which is a step that is missing from the recipe.

Brown chicken in skillet about 10 to 15 minutes in oil.,Add butter and leeks; saute with chicken until leeks are tender.,Take out chicken; set aside.,Add wine, salt, pepper and mustard.,______,Add whipping cream; stir constantly for about 1 to 2 minutes (sauce should be smooth).,Pour sauce over chicken; sprinkle chopped tomato on top.
Stir and cook on medium heat for about 1 to 2 minutes.