Cook the bacon: In a large 4.5-quart soup pot, cook the bacon over low heat until crisp, cutting the strips in half first for even cooking. Remove and drain on paper towels, then chop into small pieces. Reserve 2 tablespoons of bacon drippings in the pot.

Prepare the pot base: Carefully wipe out any burnt bits but keep the flavorful browned bits in the pot.

Sear the chicken: Season the chicken with seasoning salt. Heat avocado oil over medium-high heat in the pot, then sear chicken pieces about 3 minutes per side until golden. The chicken will finish cooking in the soup. Set aside and rest for 10 minutes before chopping into bite-sized pieces.

Cook the vegetables: Return bacon drippings and butter to medium heat. Add diced shallot, carrots, and celery. Cook for about 5 minutes until softened.

Add seasonings: Stir in minced garlic, crushed red pepper flakes, soy sauce, parsley, thyme, Italian seasoning, mustard powder, and white pepper. Cook for 1 minute.

Thicken the base: Sprinkle in flour and stir constantly for 1-2 minutes to cook out raw flour flavor.

Add liquids: Slowly pour in chicken stock while stirring to avoid lumps and scrape up any stuck bits. Stir in heavy cream.

Cook the potatoes: Add peeled and cubed potatoes. Bring soup to a boil, then reduce to simmer.

Add chicken: Return chopped chicken and any juices to the pot. Simmer uncovered or partially covered for about 20 minutes, until potatoes are tender.

Finish soup: Lower heat to low and stir in shredded cheddar until melted. Mix in half of the chopped bacon, reserving the rest for garnish.

Serve: Ladle soup into bowls and top with remaining bacon and chopped green onions.