。
I hear you're a good cook.
Literal
Cooking [subject-が] honorable-skillful [quotative-と] am-hearing.
お上手 adds the honorific prefix お~ to 上手, making the compliment more deferential. ~と聞いている (I hear that) is a hearsay pattern — the ている marks the ongoing state of having heard this information. The quotative と marks the content of what was heard.