Charlie Kaufman has added more high-wattage talent to his FX comedy pilot, recruiting Sally Hawkins and Catherine Keener for key roles.

The single-camera comedy “How and Why” revolves around a man who can explain the workings of a nuclear reactor but is clueless about life. Michael Cera and John Hawkes are already set as stars.

There was no word on the specifics of the roles to be played by Hawkins (pictured right) and Keener (pictured left). If the FX Prods. pilot goes to series, Hawkins would be a series regular while Keener would be a guest star.

Kaufman wrote the pilot and is set to direct “How and Why,” which is expected to lense next month in North Carolina. Anthony Bregman, a frequent collaborator with Kaufman, is also exec producing.

Hawkins is coming off a supporting actress Oscar nom this year for Woody Allen’s “Blue Jasmine.” Keener has worked with Kaufman on such past pics as 1999’s “Being John Malkovich,” for which she earned an Oscar nom, and 2008’s “Synecdoche, New York.”