Preheat your oven to 375F (190C) and lightly grease a 9x13-inch baking dish.
In the prepared baking dish, combine 1.5 lbs diced chicken breast, 1.5 cups uncooked orzo pasta, and 1 pint halved cherry tomatoes.
Whisk together 2 cups chicken broth, 1 cup heavy cream, 1 tbsp minced garlic, 1 tbsp Italian seasoning, and 1 tsp each of salt and pepper. Pour this mixture over the chicken and pasta.
Cover the dish tightly with aluminum foil and bake for 35 minutes.
Remove from the oven, carefully take off the foil, and stir in 3 cups fresh baby spinach and 4 oz crumbled feta cheese until the spinach wilts.
Return to the oven uncovered for another 5 minutes until the cheese is melted and the sauce thickens. Serve hot.