The Quahog Grill is where Lois takes Jesus out for lunch to find out what he likes in girls when Peter tries to help him lose his virginity in "The 2000-Year-Old Virgin".
After Peter's crude attempts at a hook-up fail, they go out to lunch together and Jesus explains that he just isn't comfortable with most girls. Lois assures him to just be himself and he'll have success. However, as a result of their day out, Jesus tells Peter that he would like to sleep with Lois.
Meg, Peter, Lois, Bruce and Phil & Candy Straight eat dinner at the Quahog Grill in "Meg's Wedding".