Preheat oven to 375 degrees F (190 degrees C).
Into a pan over medium-low heat, add Canola Oil (2 tablespoon). When warm, add White Onion (1) and Green Bell Pepper (1). Cook for 5 minutes
Cut Potato (2 pound) into 1/4-inch thick slices. Keep them in a bowl of water to prevent browning.
Into a large mixing bowl, add potatoes, cooked vegetables, Heavy Cream (1 pint), Shredded Mozzarella Cheese (1 1/2 cup), and Salt and Pepper (to taste). Stir to combine, then transfer to a 13x9-inch casserole dish.
Top with additional salt and pepper, and Shredded Mozzarella Cheese (1/2 cup).
Bake for 1 to 1 1/2 hours, or until cheese is brown and bubbly on top. Once baked, allow to stand for at least 10 minutes before serving.
While it's baking, prepare the schnitzel. Pound the Boneless, Skinless Chicken Breast (3) out very thinly.
Into one bowl, add Panko Breadcrumbs (1 1/2 cup), Salt (1/2 teaspoon), and Ground Black Pepper (1/2 teaspoon). Into another, add Large Egg (2). Into a final bowl, add All-Purpose Flour (1 cup).
Coat the chicken in the flour, then the egg, then the breadcrumbs. Set onto a plate. Repeat with other chicken breasts.
Into a large pan over medium heat, add Canola Oil (1/4 cup). Once warm, add chicken and cook until golden brown, about 3 minutes on each side. Set on a wire rack to drain excess oil.
Into a new pan, add Unsalted Butter (6 tablespoon). When the butter starts to brown, add Lemon Juice (2 tablespoon). Remove from heat and swirl the pan around.
Drizzle lemon butter sauce over the chicken schnitzel. Serve potato gratin on the side. Enjoy!