Heat oil in pan over medium heat.
Boil penne pasta 9-11 minutes. Drain.
Add mushrooms to oil. Stir.
Add butter. Stir.
When mushrooms are tender and start to brown, they are almost done.
Pour cooked pasta into a serving bowl.
Add tomatoes to mushrooms.
Add basil leaves. Stir and cook 1-2 minutes.
Pour mixture over pasta.
Add salt and pepper if desired. Sprinkle with feta. Serve and enjoy!