Cook orzo according to package directions, omitting salt and fat.
While orzo cooks, heat 2 teaspoons olive oil in a large nonstick skillet over medium-high heat. Sprinkle chicken with salt, black pepper, and red pepper. Add chicken to pan, and cook 4 minutes on each side or until done. Remove chicken from pan, and keep warm. Add the remaining 2 teaspoons olive oil and bell peppers to pan; sauté 2 minutes. Add oregano and garlic; sauté 1 minute. Remove from heat, and stir in lemon juice.
Combine orzo and feta, and serve with chicken and bell pepper mixture.