Begin by slicing the cremini mushrooms and thinly slicing the onion. Mince a few cloves of garlic to ensure you have a fragrant base. Gather all your ingredients, including the chicken thighs or breasts.

In a skillet over medium heat, add a drizzle of olive oil. Sauté the sliced onions for 3–4 minutes until they soften and become translucent.

Transfer the chicken breasts or thighs into the slow cooker. Add the sautéed onions (if seared), mushrooms, and minced garlic on top.

In a separate bowl, whisk together the balsamic vinegar, chicken broth, soy sauce, honey, dried oregano, thyme, salt, and pepper.

Slowly pour the prepared sauce over the ingredients in the slow cooker, making sure everything is well coated.

Cover the slow cooker with its lid and set it to low for 6–8 hours or high for 3–4 hours.

If you prefer a thicker sauce, remove the chicken and mushrooms from the slow cooker once cooked. Whisk together cornstarch and water, then stir this mixture back into the sauce and cook on high for an additional 10–15 minutes.

Once thickened, place your chicken and mushrooms back in the sauce to coat. Serve over mashed potatoes, rice, or pasta, garnished with freshly chopped parsley.