City O' City is a quirky breakfast/brunch spot (they do dinner but I associate it with brunch for some reason) in the hipster Capitol Hill neighborhood of Denver. Located near lots of fun coffee shops, record stores, and art museums, City O' City is a great place to stop by for locals along with tourists looking to get out of the main Downtown Denver promenade.
They have many options for gluten free diners including various omelettes, oatmeal, and waffles. I was discouraged the first time I came here for breakfast because I wanted to order the oatmeal (marked on the menu as GF), but when I double checked with the waitress, she couldn't confirm that the oats were actually GF certified. However, this was quickly made up for when I ordered the Savory Waffle. All the waffles at City O' City are gluten free and not at risk of contamination because no gluten ever touches the waffle iron. The Savory Waffle is a bulky waffle that has more of a multigrain flavor than a sweet waffle, and it is then topped with fresh seasonal vegetables cooked to perfection, then drizzled with a fondue that is to die for. Get a fried egg on top for an extra dollar and you won't regret it.
If you're in the Capitol Hill neighborhood, I can't recommend City O' City enough- just promise that you will try the savory waffle.