Step 1: Prep the Oven and Dish
Preheat your oven to 375°F. Lightly oil a 9×13-inch baking dish with olive oil.

Step 2: Prepare the Cheese Mixture
In a large bowl, combine the shredded mozzarella, drained cottage cheese, chopped scallions, beaten eggs, Italian herb blend, and salt and pepper. Mix until everything is well combined and set aside.

Step 3: Sauté Chicken and Vegetables
Heat the 2 tablespoons of olive oil in a large, deep skillet over medium-high heat. Add the sliced zucchini and thick-sliced mushrooms. Sauté, seasoning with salt and pepper. After a few minutes, add the salted, cubed chicken breasts and continue cooking for 5 minutes, or until the chicken pieces are lightly golden on the outside.

Step 4: Drain and Combine
Transfer the entire contents of the skillet (chicken and vegetables) into a colander to drain any accumulated liquids. This is a crucial step to prevent a watery bake! Once drained, immediately transfer the contents into the bowl with the prepared cheese mixture and toss gently until everything is fully incorporated.

Step 5: Assemble and Bake
Transfer the entire mixture into the prepared 9×13-inch baking dish. Pat the mixture down with a spatula to form a smooth, even layer. Top the entire surface with the 2 tablespoons of grated Parmesan. Bake for 30 to 40 minutes, or until the top is golden brown and the edges are actively bubbling.

Step 6: Rest and Serve
Remove the dish from the oven and let it rest for 5 to 10 minutes prior to slicing and serving.