Serena Williams just revealed her latest project, and not only is it unlike any other she's ever done, but she's pairing up with a totally unexpected star for it.ALSO: HELLO! launches Jubilee T-shirt collection to celebrate Queen Elizabeth in styleThe tennis player is spending time in the kitchen rather than the tennis courts, announcing that along with actor Jake Gyllenhaal, she is JUST Egg's brand new ambassador.The vegan cult-favorite brand is known for their innovative egg substitute, which cooks, fries and scrambles just like regular eggs.WATCH: Serena and her daughter Olympia's matching outfits are impossibly cuteMORE: Serena Williams stops tracks in stunning black dress for new photoBoth stars are already investors of the science-forward food and wellness company, and starred in hilarious ads poking fun at their own careers to promote the partnership.For Serena's, she's seen getting ready to have breakfast in her kitchen, as a narrator says: "You think the G.O.A.T.