Trader Joe's is an American chain of grocery stores headquartered in Monrovia, California. The chain has over 530 stores nationwide.
When Francine gives Stan her prize of becoming a firefighter for a week in "A Song of Knives and Fire", he is overjoyed at first, but finds out he's primarily relegated to making casseroles and doing grocery runs to Trader Joe's. When Francine makes a grocery run of her own, she sees Stan and decides to spice things up for him by starting a fire in a dumpster for him to put out.