In general I have found it best to leave off the "s" for most foods. The search engine will find stuff that you give an incomplete spelling for, but if you give it too much information and it doesn't find and exact match you can get some pretty odd returns.
For example, since I am a lousy speller rather that typing in "broccoli" I will just type "broc" and it will find all the things that have those 4 letters. Broccoli, raw usually comes up in the first few lines. Likewise, since I can't seem to remember how to spell mayonnaise correctly, I just type "mayo" and all the choices for mayonnaise will show up on the first page.
I also tend to log most of my foods as "raw" and add whatever additional items I included in the dish. For example scrambled eggs with veggies will be logged as: egg raw (2 large), sweet pepper (.5 large), butter (1 tbsp) etc.
And as a last resort I will just create a custom food for something I keep having difficulty finding like "steak". Don't why it isn't easier to find, but hey, sometime ya just gotta work with what ya got.