Without a context, it's hard to interpret the sentence. However, here's one possibility. The employees of a tavern (bar) buy a beer which has little alcohol content. We can call such a beer "weak." He prefers a "strong" beer for his customers. So the owner of the tavern tells his employees, "Get this weak stuff out of my kitchen. = "Get rid of this weak beer.") "And go get some stronger beer (beer with more alcohol content)!"

"Weak" could be referring to tasteless or sub par food or beverage (or alcohol).

modern family, right?