Heat 1 tablespoon of butter over medium heat in a Dutch oven. Add celery and carrots. Cook covered for 8 minutes stirring occasionally.
Melt remaining butter in a pot and whisk in gluten-free flour. Cook 30 seconds.
Add chicken stock to pot and stir, scraping up browned bits on the bottom of the pot. Reduce heat to medium-low and stir in chicken and poultry seasoning. Bring it to a simmer. Simmer for 5 minutes.
Add milk and peas and stir until thoroughly combined and thickened. Cook 5 minutes longer. Season with sea salt and pepper to taste.
Divide chicken stew between large compartments of 4 containers.
Optional Add 12-13 crackers to each small compartment.