Cook pasta in salted water according to package instructions, then drain and set aside.

Heat olive oil in a skillet, sauté minced garlic until fragrant but not browned.

Lower heat, then whisk in Greek yogurt, milk, and parmesan cheese until smooth and creamy.

Add cooked chicken, salt, and pepper, stirring gently to combine.

Toss cooked pasta into sauce, mixing until evenly coated and heated through.

Add spinach if using, cook briefly until wilted, then serve immediately.