While I have not been there in several years, it would depend on the Denny's and what the waitstaff/cooks were like and what was ordered. If you are careful and have a good waiter, plus have good back and forth communication (this is where the word "allergy" comes in handy, altho technically incorrect) you can get a few items there to make a meal. ( I wouldn't do this at a lot of Denny's, just the 2 I have been to in this one town near here. When I explained I needed a side dish, to go with 2 plain eggs, they made me a fruit cup out of all fresh fruit. I was really grateful for this. You know how it goes sometimes, when you really need to eat and still have a long trip to reach home. ) I would not do the hash browns, however, or anything not cooked on a clean surface. You could pick up cross contamination from the grill, or the hash browns could have had preservatives in them to keep them from browning when frozen. You are also at the mercy of their food suppliers, they (the kitchen manager) may order something for the week or the month, but get another product in which is not updated on their menus.