Prepare the Cornstarch Slurry: In a small bowl, whisk together the cornstarch with 4 tablespoons of cold water until smooth. Set aside.
Sauté the Vegetables: Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion, carrots, and celery. Cook, stirring occasionally, until the vegetables start to soften, about 5-7 minutes.
Add Garlic: Add the minced garlic to the pot and cook for another minute, until fragrant.
Pour in Broth: Pour the chicken broth into the pot. Bring the mixture to a simmer.
Add Potatoes and Seasoning: Add the diced potatoes, dried thyme, salt, and black pepper to the pot. Stir well to combine everything.
Simmer: Cover the pot and let the mixture simmer for about 15-20 minutes, or until the potatoes are tender when pierced with a fork.
Add Chicken: Stir in the drained canned chicken. Make sure the chicken is heated through, which should take about 5 minutes.
Thicken the sauce: Add the cornstarch slurry to the pot. Continue stirring until the sauce has reached your desired thickness.
Garnish and Serve: Remove the pot from the heat. Garnish with fresh parsley, if desired. Serve hot, and enjoy your quick and easy chicken dinner!