Web Api Design advice

I am developing a Web API as services layer for a Asp.Net web forms application. There are two controllers ContractorController (gives details about the Contractor) and PaymentsController (gives details about payments done to a contractor).

Now in our UI application we have this User-Control which will be used across many pages.

Is the responsibility of UI to call the ContractorController and PaymentsController separately to get the required data? Or should I provide a Consolidated Method (may be on Payments Controller) to give back all the required data, which seems to be going against RESTful approach or dealing with resources?

Thank you.