Combine the cream of chicken soup, sour cream, chicken bullion, and poultry seasoning in the slow cooker and mix well.

Stir in the frozen vegetables and diced onion. Nestle the chicken into the soup mixture.

Cook on high for 2.5-3 hours, or low for 3.5-4 hours. Chicken should be 165˚F internal temperature when done.

Remove chicken and shred, then stir back into the mixture.

Crush the Ritz Crackers into a fine crumb. Mix the crumbs with the butter, then toast them in a skillet over medium heat until they are golden brown, about 3-4 minutes.

Alternate method: Spread crumbs on a baking sheet and bake at 350˚F for 5-8 minutes or until golden brown.

Serve a scoop of the chicken pot pie, topped with a spoonful of crumbs.

You can also top the whole chicken pot pie with the crumbs, but keeping them separate is recommended for leftovers.