The "Define New Recipe" function on myalliplan allows you to enter your own recipe, but you have to provide the nutritional data. I don't know of anywhere on the site to actually enter a full recipe and get the nutritional data from those ingredients.
However you can do that at this site:
www.nutritiondata.com
Once you set up your "pantry" of items you are cooking with it is pretty thorough and straightforward.
Best of success to you,
Jim