Cook pasta according to the directions on the box; set aside.
Heat olive oil in a skillet over medium-high heat.
Add garlic and cook for 1 minute or until fragrant.
Stir in flour; stir until combined.
Slowly whisk in chicken broth.
Cook and stir until mixture boils and thickens; remove from heat.
Stir in parmesan cheese; stir until melted.
Whisk in the yogurt; whisk until combined.
Season with dried parsley, salt and pepper.
Sauce will continue to thicken as it stands. If sauce is too thick, add a little more milk.
Pour sauce over cooked fettuccine; mix until combined.
Transfer to plates and top with previously prepared chicken.
Garnish with basil ribbons and serve.