Preheat the broiler to high and position the rack to the center of the oven. Cook penne according to package directions. Add broccoli florets during the last 2 minutes of cooking; drain well. Meanwhile, heat oil in a large nonstick ovenproof skillet set over medium heat. Add chicken and season with 1/2 of the salt and pepper (use the rest to taste). Cook, stirring occasionally, for 5 minutes or until golden brown all over. Stir in onions, sundried tomatoes and garlic. Cook for 5 minutes or until onions have softened.
Stir in the tomato paste; cook for 1 minute. Stir in strained tomatoes and simmer for 5 to 7 minutes or until thickened. Remove from heat. Toss with cooked penne and broccoli. Let stand for 10 minutes. Stir in yogurt. Sprinkle with mozzarella and Parmesan. Broil for 5 minutes or until cheese is melted, bubbling and golden brown.
Add a pinch of hot pepper flakes for a spicy kick.