Stock is a flavoured liquid preparation. It forms the basis of many dishes, particularly soups and sauces. Making stocks involves simmering animal bones or meat, seafood, or vegetables in water or wine, adding mirepoix or other aromatics for more flavour.
Whoopie pies are like the best parts of a cupcake squished into one delicious sandwich. That would be the top of the cupcake and the frosting, of course.
Nate's watching TV when his mother comes in, dressed in conspicuous clothing, then sheds them to reveal that she had done so because she had just bought a Whoopie Pie from Banter Bakery, which Nates notes that bakery has the chef being noted as an absolute perfectionist with his crafts, selling none that's no less than perfect.