In a large pot of boiling water, cook penne until al denta. Drain and set aside.
In a large skillet over medium-high heat, melt butter, add olive oil. Add garlic, onion and red pepper. Cook for 2-3 minutes, add diced chicken and cook until chicken is done. (6-8 minutes).
Reduce heat to medium, add lemon juice, chicken stock, artichoke hearts, oregano, diced tomatoes, and olives. Stir to combine and allow to heat through. Add penne pasta and fresh spinach. Cook just until spinach begins to wilt. Stir in feta cheese.
Enjoy. Serves 4-6 people.