Place the chicken breasts into the bottom of a 5 or 6 quart crockpot.
Spread the thinly sliced yellow onion over the chicken breasts.
In a bowl mix onion soup, beef broth, and Dijon mustard.
Pour over the chicken.
Cover the crockpot with its lid.
Cook on low heat for 4-5 hours, or until the chicken is tender and fully cooked. Cooking times may vary depending on your crockpot model.When done, taste for seasoning and add salt and pepper to your tastes.
During the last 30 minutes of cooking, sprinkle the grated Swiss cheese over the chicken.
Cover the crockpot again and allow the cheese to melt and become bubbly.
Once the cheese is melted and the chicken is cooked through garnish with freshly chopped parsley..
Serve the Crockpot French Onion Chicken hot with your choice of sides, such as rice, a salad, mashed potatoes, or crusty bread.
Notes
Please refer to my FAQ’s (Frequently Asked Questions) and ingredient list above for other substitutions or for the answers to the most common questions.