Bring a large pot of salted water to a boil and cook the penne pasta according to package directions until al dente; drain and set aside.
Season the chicken strips with salt, pepper, and oregano.
Heat olive oil in a large skillet over medium-high heat. Add chicken and cook for 5-7 minutes until golden brown and cooked through. Remove chicken from skillet and set aside.
In the same skillet, sauté minced garlic and sun-dried tomatoes for 1-2 minutes until fragrant.
Reduce heat to medium and pour in the heavy cream. Bring to a gentle simmer.
Whisk in the Parmesan cheese and red pepper flakes until the cheese is melted and the sauce thickens.
Stir in the fresh spinach and cook until wilted.
Return the chicken to the skillet and add the cooked pasta. Toss thoroughly to combine with the sauce.
Serve immediately.