Directions

1. Preheat oven to 375°F.
2. Cook the penne pasta until al dente.
3. Heat the olive oil in a large skillet over medium heat and sauté the onion and garlic until softened.
4. Add the cooked chicken, mushrooms, spinach, milk, flour, and Italian seasoning. Season with salt and pepper and stir until thickened.
5. Add the pesto and cooked pasta. Stir until well combined then transfer everything to a casserole dish.
6. Top with the mozzarella cheese and bake for 20 minutes, until the cheese is browned and bubbly.
7. For the homemade pesto, combine everything except the olive oil in a food processor or blender.
8. Blend until mixed and smooth.
9. With the motor running, slowly stream in the olive oil and blend until just combined (you don't want it to be soupy).