What side dishes work well with this? It already has a veggie, grain & cheese in it.

This is a pretty filling preparation in itself since it packs in quinoa, turkey, and cheese which is why it's classified as a one-dish meal.

Invariably I would serve something like a simple salad to offset this dish's inherent heaviness. But that's just me...

Ultimately it's your call. Serve whatever you think would please the people who will join you at your dinner table.

Best of luck.

As you note, this dish already has three main nutrients - veg, carb, protein.

Hard to think of a side.

How about a first course instead - small cups of soup, or some kind of dip and crackers - to round out the meal.