Boil pasta in salted water until al dente and drain. Set aside. Reserve 1/4 cup of the pasta water for later use.
Using a meat mallet pound the chicken breasts to an even thickness. Sprinkle 1/4 teaspoon salt and 1/4 teaspoon pepper on both sides of each chicken fillet.
Place a large skillet with 1 tablespoon olive oil over medium heat and add chicken. Cook fillets until golden, turn over and reduce heat to medium-low. Cover skillet with a lid and cook 10 additional minutes.
After 10 minutes, turn heat off and make sure chicken is cooked through. Remove fillets and slice each into 1-inch medallions. Place on a plate and cover with foil while cooking mushrooms.
In the same skillet turn to medium heat, add remaining olive oil and mushrooms, cook for 5 minutes, stirring occasionally, until mushrooms are lightly browned. Add tomatoes and garlic and cook for 1 minute. Add pasta and pasta water, and toss to combine. Cook for 1 to 2 minutes, or until warmed through, remove from heat. Toss in chopped basil.