Yes poppies is right in a way. if you know you have something in kitchen, like juice or cold drinks , just get the tray ready and put it infront of them.
And if he is not inside the home yet and on gate, you can say , Uncle plz ander aa jaain, aap pehli baar humaray ghar aain hain. Khana kha kar jaain. etc. He will most prolly say.. nahin beta thank you phir kissi aur din sahi. abhi jaldi hai. Then u can say to ur friend... Beena (for exmple) ab tumhari zimma-daari hain uncle ko dobara laana. then give a huge smile to both and Allah Hafiz.
You do not have to be soooooooooooooooooooo formal with guests specially when u do not know them, and not free with them. Coz if you act so formal they may take it in wrong way too. Believe me this happens.
Btw if you really want to stop someone for lunch or dinner or tea, the words will come out of you naturally.
PS. you dont have to do ..kijiey lijiye rakhiye jaaiye aaiye.... no one uses such words now days. just say kar dain, kha lain, lay lain, aa jaain, bhaar mein jaain ;) etc.
haaaahaaa............bharr mein jaain ;):Di ought to say that