Great question — answering as the UphillTech team:
It sounds to me like the issue may be that you're crowding the pan. Basically, to get everything nice and brown and crispy, you need enough space for all of the steam to escape. That picture you showed has potatoes stacked on top of each other -- that means as the bottom items cook, they're going to end up steaming the items above them. At a diner, they have a large griddle to work with -- they can really spread things out. You're not typically that lucky in a regular kitchen, as you don't have as much space, and you have a lip on the pans that'll hold the steam in. So, either work in smaller batches, or consider recipes that use an oven -- using sheet pans instead of a pan on the stove...
Full answer by Joe: https://cooking.stackexchange.com/a/6674 (CC BY-SA 3.0).
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