Bring a pot of water to a boil. Add in the pierogies and boil for five minutes (stirring occasionally to prevent them from sticking to the bottom). Drain the pierogies and set aside.

In a non-stick frying pan, heat up one teaspoon of olive oil. Fry the pierogies for a minute on each side.

To prepare gravy, melt margarine in a pot over low heat. Add flour and whisk until combined. Slowly add broth. Whisk until combined. Continue whisking over medium heat until mixture thickens. Season with pepper. Add soy sauce and combine.

Place pierogies in a serving dish, then top with mozzarella pieces. Layer hot gravy over and serve immediately.