Backstory: Lately we've been cooking more often and having fun looking up random recipes online. We've run into a time consuming portion where we have a set of unique recipes we want to create for the week and then have to convert to a shopping list. It's rather time consuming and we often buy items we already have.

The Idea: Covert recipes to a shopping list.

Deep Dive: You would build a service that could ingest a set of recipes from sources like pinterest, aggregate the ingredients and put them in an easily downloadable format. Most likely your end user is going to be on their phone. 

There are lot of variations to this, here are a few:
1. Track your user's current ingredient list and only have them pick up items they need
2. Coordinate with their local grocery store and list the ingredients in order of pickup (through the isles)
3. Upload the ingredients to your user's local store for pickup.

Validation: Companies like supercook already do portions of these.

Monetization: You could charge a monthly fee or a per export fee.

Steps to Launch: I would start with one recipe website and work on ingesting those recipes and aggregating the ingredients into a simple text message or email. There are lot of moving parts on this one and keeping it simple will help validate the idea.