Preheat oven to 350 degrees. Season cubed chicken breasts with 3/4 teaspoon of salt, 1/4 teaspoon of black pepper and 1/2 teaspoon of Italian seasoning. Bake for about 20 minutes. The chicken needs to be either completely baked or almost completely cooked through.
Drizzle about 1/2 to 1 tablespoon of olive oil to a medium to large skillet over medium heat. Add zucchini and onion. When zucchini is almost cooked, about 10 minutes, add garlic. Stir to combine. Add about 1/2 teaspoon of salt and Italian seasoning and 1/4 teaspoon pepper to skillet. Stir and cook for about 3-5 more minutes. Add block of softened cream cheese. Stir until it is melted.
Add canned tomatoes and cooked chicken to skillet. Stir until all ingredients are combined. Pour into a 9×13 dish and top with cheese.
Bake for 10-15 minutes, until everything is hot and cheese is melted.