Bring a large pot of salted water to a boil. Add the pasta and cook according to the package directions until it's al dente, usually about 8-10 minutes.
Drain the pasta and rinse it with cold water.
While the pasta cooks, prepare the chicken: Brush the chicken with olive oil and season with Italian seasoning. Grill over medium-high heat for 8-10 minutes or until cooked through.
Remove the chicken from the grill and let rest for 5 minutes. Cut into bite-sized pieces.
Add the cooked pasta to a large mixing bowl. Add the chicken, peppers, cucumber, green onion, and sunflower seeds.
In a small bowl, whisk together the lemon juice, remaining olive oil, and honey. Season to taste with sea salt.
Pour the dressing over the pasta salad. Mix well until everything is combined. This salad can be served immediately but is even better when refrigerated for at least 1 hour.