Dice the chicken into bite-sized pieces.

To a large, high-sided skillet or Dutch oven, add the olive oil, chicken, generously season with salt and pepper, and cook for about 2-3 minutes over medium-high heat to sear the chicken; flip and turn frequently. Remove it after it's seared on all sides and set aside in a bowl.

Add the butter, mushrooms, diced onions, reduce the heat to medium-low, sauté for about 6-7 minutes or until the mushrooms have shrunk in size and are tender; stir very frequently.

Add the garlic, thyme, dried parsley, evenly sprinkle the flour, and cook for 1-2 minutes. There should be no visible clumps or lumps of flour; stir with a wooden spoon nearly continuously.

Slowly add the chicken broth while stirring continuously. Slowly add the half-and-half, Worcestershire sauce, simmer for 3-4 minutes over medium-low, or until it has thickened slightly; stir very frequently.

Add the chicken back in, cover with a lid, reduce the heat to low, and simmer for about 15 minutes covered, or until done.

Uncover, taste the soup, and as necessary, add salt and pepper.

Optionally, if you'd like to add greens or veggies, feel free to add a few handfuls of fresh spinach leaves, kale, chard, or frozen peas and allow them to soften and wilt for about five minutes; stir frequently.

Depending on how thick you like your soup, you can either simmer uncovered for a few minutes to encourage it to thicken more. Or, if it's too thick for your liking, feel free to add additional chicken broth and/or a splash more of half-and-half, as desired.

Optionally, garnish with fresh parsley and serve immediately.