Caramelize the onions

• Melt the butter in a frying pan over medium heat.
• Add the sliced onions and sauté until soft and golden.

Load the slow cooker

• Place the chicken in the slow cooker and add the sautéed onions.
• Pour in the beef broth and chicken broth.
• Season with salt, pepper, garlic powder, thyme and a dash of Worcestershire sauce.

Cook low and slow

• Cover and cook on high for 3–4 hours or on low for 6–7 hours, until the chicken is tender.

Add the cheese and serve

• Shred the chicken in the sauce, then top with the shredded Gruyère and let it melt.
• Serve with mashed potatoes or rice.