Combine chicken broth, lemon juice, minced garlic, oregano and chicken bouillon in slow cooker then stir to dissolve bouillon. Once bouillon has dissolved, add chicken and butter.
Cover and cook on low for 2 hours or just until chicken is cooked through and tender. Overcooking chicken breasts will result in them becoming dry.
Remove chicken from slow cooker, dice, slice or leave breasts whole then transfer to a serving dish.
Stir together cornstarch and water in a medium saucepan. Add the liquid from the slow cooker to the saucepan. Place over medium-high heat and bring to a boil, whisking continuously. Once sauce comes to a boil, reduce heat to low and simmer 1 minute. Remove from heat.
Add salt and pepper to taste. Add a few drops of fresh lemon juice for a little more zing or a pinch of sugar if it’s a bit too tart. Pour sauce over chicken, garnish with fresh chopped parsley then serve over rice or pasta with a lemon wedge on the side.
One Last Thing
If you like a perfect presentation with nicely-browned chicken breasts, you can brown them in the butter on the stove top and then add them to the slow cooker.