In 2005, Tressl showed that there is a theory of differential fields, called UC, such that whenever T is a model complete theory of large fields, T + UC is the model companion of T + "differential fields". This gave a uniform way of constructing model companions of differential fields, and put many of the well-known examples of differential fields inside a common framework. In this talk I will show how we can extend Tressl's result to the case of fields with free operators—fields equipped with a homomorphism from the field to its tensor product with some fixed algebra D. Fields with free operators have definable endomorphisms, and thus constructing the uniform companion must be done relative to the underlying difference field. We will introduce the necessary generalisations of field-theoretic notions to the difference case in order to facilitate this.