Prepare all of the ingredients. Preheat oven to 400deg.
In a sauce pan over medium-high heat, add chicken, dried onions, tarragon, and garlic cloves. Add water until 2 inches over chicken. Bring to boil and cook for 8 minutes (it will not be totally cooked, but that okay). Remove chicken from pan and reserve liquid (scrape any foamy stuff offtop). Chop chicken into bite-size pieces.
Bring chicken broth back to boil and add rice to pan. Continue in a rolling boil for 6 minutes. Add broccoli to boiling rice and cook another 4 minutes. Should have about a cup of liquid left. Transfer rice, broccoli and remaining broth to a 13x9 baking dish.
Add chicken, cream cheese, pepper jack and cheddar cheese to rice and brocolli. Stir to combine.
Add panko, parmesan cheese, and garlic salt to melted butter. Sprinkle over top of rice and chicken. Place in oven for 20 minutes. Let rest at least 5 minutes befor serving.