How to Make It
Cook pierogies according to package directions. Drain, reserving 1/2 cup of cooking liquid; cover pierogies to keep warm.
Spray a large skillet with non-stick vegetable spray. Add frozen vegetables; cook until tender and golden and most of the liquid is cooked off. Stir in tomato sauce and reserved liquid; heat through.
Toss vegetable mixture with pierogies; season with salt and pepper.
101 Hearty Recipes Cookbook