To keep it simple pasting a list of ingredients and even whole recipies into the text field is the most flexible.
Search can help.
However we then have the opportunity to add value through meta data and curation.
Lets say I like having people over for dinner then I may select a number of dishes I have found popular and easy to multiply to feed more people.
- with those recipies I would be happy transfer the key ingredients into seperate entries with qty and units
then I can select and create a list to check my cupboards or a shopping list.
- or list what i have and identify what i can cook.
To me we need to keep in mind how we can help make it easy to tap into more sophisticated uses.
Let people be casual, store simple fuzzy data but give them the tools to match what their motivations drives them to do.