Add tomatoes, feta, garlic, and chicken to a casserole dish. Drizzle olive oil over the top and season with salt and pepper. Place in the oven for about 30 minutes.
In the meantime, in a pot of salted boiling water, cook the pasta according to the directions on the package. Drain well then set aside.
Take the casserole dish out of the oven and immediately start to mash the cherry tomatoes and cheese together using a whisk. Stir in the pasta until everything is incorporated. Taste and season with salt if needed.