Cook the penne pasta in a large pot or Dutch oven according to the package instructions.

Drain the pasta and return it to the pot.

Add the chopped plum tomatoes, fresh spinach, olive oil, Greek seasoning, salt, and dried crushed red pepper flakes to the pot with the cooked pasta.

Cook the mixture over medium heat for about 2 minutes, or until everything is thoroughly heated and the spinach starts to wilt.

Sprinkle the crumbled feta cheese over the top of the pasta.

Serve your Spinach and Feta Penne Pasta immediately, and enjoy as a delicious side or main dish.

This pasta pairs well with steak or makes a satisfying vegetarian meal on its own.