To solve this problem, I created my first LLM-based webapp "recitube" (stupid name, I know). It fetches the youtube transcript for a given video and uses Llama3-8b to extract the ingredient names. I get valid json from the model about 9/10 times :D
At this time it simply displays search links to Walmart & Amazon, but I want to further simplify things by offering a single-click "add-to-cart" option. It appears as if I'd need to become Walmart/Amazon affiliate to gain API access that would allow me to do that :/