Combine gumbo file, sea salt, dry mustard, thyme, cumin, bay leaves, cayenne, salt and black pepper in a bowl and set aside.
Heat a 12-in. Calphalon nonstick omelette or 3-qt. sauté pan over medium heat until the rim is hot to the touch. Add 2 Tbsp. olive oil. Heat for an additional minute.
Season chicken with salt and black pepper and brown on all sides. Transfer chicken to a bowl.
In the same pan, brown sausage and transfer to the same bowl as chicken.
In the same pan over medium heat, heat 1 Tbsp. olive oil and sauté onions for 2 - 3 minutes or until they become soft.
Add celery, red pepper and garlic and sauté for another minute. Transfer to a large bowl.
Add spice mixture and rice to vegetables and stir to combine ingredients. Add chicken and sausage to a slow cooker crock. Top with rice mixture and stir in stock.
Cook for 2 hours on High.
Add shrimp and tomatoes and stir to combine. Cook for an additional 30 minutes on Low.
Remove bay leaves, stir in parsley and check for final seasoning adjustment (salt & pepper) and serve.