Some combinations I like:
Feta, frozen spinach or kale (warmed up and water squeezed out), roasted red peppers from a jar.
broccoli and cheddar
Mushrooms sauteed in smoked paprika, red chili powder, and cumin with jalapeno Monterey Jack cheese and frozen corn
I'm looking to do one with roasted butternut squash and kale and maybe some kind of smoked cheese?