Cook The Bacon. In a large Dutch oven or soup pot, cook the diced bacon over medium heat until browned. Remove the bacon from the pot and place on a small plate. Drain the bacon grease from the pot.
Add Green Onion, Garlic, Salt, and Pepper and stir, cooking just 1-2 minutes, or until fragrant.
Cook The Rice. Pour in chicken broth, water, and wild rice and stir to scrape up any browned bits from the bottom of the pot. Bring soup to a simmer over medium high heat and cook 30-35 minutes, stirring occasionally, until rice is mostly tender (it'll still have some bite!)
Meanwhile, Make the Roux. When the rice is almost tender, start the roux. In a small saucepan, melt butter over medium heat. Add gluten-free flour and whisk this flour mixture 2-3 minutes or until the mixture is very smooth and the flour is starting to toast. Gradually whisk in the half and half and stir to combine. Continue cooking over medium heat until the mixture is thickened, about 3-5 minutes.
Finish The Soup. Add chicken, bacon, pimentos, and the gluten-free roux to the soup and stir to combine. (At this point, the soup will look a little thin.) Continue cooking on low heat 15-20 minutes to allow the soup to thicken. It will get thicker the longer it cooks, and will thicken more as it cools.
Ideally, Let The Soup Sit. If you have time, let the soup continue to cook covered on low heat up to an hour longer, stirring occasionally, to allow the flavors to develop. (Or, prepare the soup in advance and refrigerate overnight!) If the soup thickens too much, add a splash of water or broth to thin it back out.
Serve & Store. Garnish the soup with a sprinkle of fresh chives or fresh parsley, if desired, and enjoy warm. Store leftover soup in an airtight container in the fridge 3-4 days. (This soup doesn't freeze well, since the creamy texture can separate.) Keep in mind that soup will continue to thicken as it cools, since the rice will absorb more liquid, so you can thin leftovers out by adding a splash of water, if needed.