Preheat a grill pan over medium heat.
Combine garlic and oil; brush evenly over pitas. Sprinkle 1/4 teaspoon salt and 1/8 teaspoon pepper evenly over pitas. Place pitas in pan, and cook 2 minutes on each side or until toasted.
Sprinkle 1/4 teaspoon salt and 1/8 teaspoon pepper evenly over mushrooms and tomatoes. Place mushrooms in pan; cook 6 minutes or until tender, turning once. Remove mushrooms from pan. Add tomatoes to pan; cook 1 minute.
Spread goat cheese evenly over pitas. Arrange the mushrooms and tomatoes evenly over pitas. Sprinkle with chopped basil.