Vader didn't comment on the food. He'd find something, eventually. For now he was entirely avoiding the issue of nourishment for his own body.

"I'm for the Empire, regardless who occupies the Throne. It is to the Empire I pleaded my loyalty, and it is not an oath I intend to betray." Liars he'd decreed some. Not one to betray his oaths. Read properly, one could understand much of Vader's person with those sentences. "Ideally the person to occupy it would be wise, concerned with making sectors work together instead of against one another." With force if needed. Or with him. "Our current Emperor pretended to be one such person until he was unmasked and showed his true self." One Vader still desired to kill.

One he may learn here secrets to do so. Among other feats.