2-3 boneless, skinless chicken breasts, cut into 1-inch squares
2 tablespoons olive oil
1 medium onion, minced
4 medium cloves garlic, minced
1/2 teaspoon dried oregano
1/4 teaspoon red pepper flakes
12 ounces ziti or penne pasta
3 cups water
2 1/2 cups low-sodium chicken broth
4-5 cups broccoli florets
1/2 cup oil-packed sun-dried tomatoes, rinsed, drained and chopped coarse
3/4 cup heavy cream
1 teaspoon cornstarch
3/4 cup freshly grated Parmesan cheese
1 1/2 tablespoons fresh lemon juice