You can do this with Flutter. Flutter provides two packages for ui: material and Cupertino. But you an make your own package using Flutter. This is something I'm doing right now in fact.
Unless I’m mistaken, the Cupertino package isn’t using real UIKit controls… they’re just Flutter controls skinned to look like UIKit and drawn to an OpenGL context. My proposed solution is built to use actual UIKit under the hood on iOS.