Chicken, Spinach, and Artichoke Rigatoni

In a large pot of salted boiling water, cook pasta. Drain, reserving 1 cup pasta water, and return to pot. Meanwhile, in a large skillet over medium heat, heat oil. Add garlic and spinach and cook until wilted, 3 minutes, then add artichokes and cook until heated through. Set aside. Add chicken to skillet and season with salt and pepper. Cook until golden and cooked through, 6 minutes per side. Set aside. To skillet, add butter and let melt. Add flour and whisk until combined, then add chicken broth, milk, and cheese. Season with salt and pepper. Return cooked pasta to skillet and toss with sauce until coated, then add spinach and artichokes and toss until combined. Garnish with Parm and serve.