Navigate to the Orders tab of your proposal and click on "Add line item" just below the section title.

Click on the icon with the two arrow at the left side of the line item to open the editing module. Then navigate to the "Recipes" tab and click on the "Recipe Ingredients" field to pull your library dropdown menu and select your item of choice.

Make sure to edit the quantities or numbers that you need per item, and change their cost per unit for this proposal only if need be.

Select the markup you'd like to apply to this recipe at the bottom of the module.

Don't forget to add notes to your recipe if you'd like!