Good way to use up frozen mixed veggies?

Yes.

I like to make large batches of rice pilaf, with browned short noodles, onions, and the frozen mixed veg. When it’s done, I freeze it in dinner-sized batches. One batch in the microwave plus a steak or a chicken breast is a complete dinner.

black bean and corn salad
tomato and corn salad (tomatoes, corn, basil, oil and vinegar)
Jiffy corn casserole
add corn to pancakes