Dice the chicken breast into bite-sized pieces and set aside.
Chop the carrot, celery, and onion into small, uniform pieces. Mince the garlic.
In a medium saucepan, add the chicken broth and bring to a gentle simmer over medium heat. Add the minced garlic, diced carrot, celery, and onion.
Once the vegetables start to soften (after about 5 minutes), add the chicken pieces. Continue simmering until the chicken is cooked through and the vegetables are tender, about 10-12 minutes. Season with salt and pepper to taste.
While the stew simmers, prepare the drop biscuit batter. In a bowl, combine the whole wheat flour, baking powder, and dried thyme.
In a separate small bowl, whisk together the egg white, unsweetened almond milk, and olive oil.
Pour the wet ingredients into the dry ingredients, stirring gently until just combined. Avoid overmixing.
Using a spoon, drop small dollops of the biscuit batter onto a parchment-lined baking sheet.
Preheat your oven to 425°F. Bake the biscuits for about 10-12 minutes or until they are lightly golden and cooked through.
Ladle the hot chicken and vegetable stew into bowls and serve with a warm, fluffy herbed drop biscuit on the side.