You can do this at
http://www.fitwatch.com/ (both the free version and the deluxe have this feature). I used it for a while. It was pretty easy to use but they have a lot of pop-up ads so I stopped using them. If you have a good pop-up blocker (I was have a number of computer problems at the time so my pop-up blocker was not as effective as it should have been) I think it would be fine.
Now I use a spreadsheet I created where I enter the ingredients and their individual nutritional info. But this does get tedious because I have to look every ingredient up every time I figure out a new recipe.
- Barbara