Preheat the oven to 425 degrees.
Cut the potatoes into 1/2-inch thick sticks. Place into a large bowl and cover completely with cold water for 10 minutes. Drain well and pat dry with a towel.
In a small bowl, dissolve the cornstarch in the water and set aside.
In a saucepan, bring the chicken and beef broth to a simmer. Whisk in about half the cornstarch mixture and simmer for a minute. If you'd like your gravy thicker, add more of the cornstarch mixture in small increments, as needed to thicken. Taste and season with salt and pepper. Set aside.
Place the potatoes in a single layer on a foil lined baking sheet. Toss with oil, season with salt and pepper. Cook for 15 - 20 minutes until they start to brown on one side, then flip the fries over using a spatula and cook until golden brown and crisp, about 15 - 20 minutes. Season with salt once done.
Preheat the oven broiler on high.
Arrange the fries into a pile and scatter the cheese curds or mozzarella over top. Then pour on the gravy. Place under the broiler for 3 to 5 minutes until the curds or cheese start to soften and melt
Taste and adjust the seasoning with salt if needed before serving.