Season both sides of the chicken breasts with salt and pepper.
Coat both sides of the chicken with flour, shaking off the excess.
Heat olive oil in a skillet over medium-high heat. Sear the chicken for about 3 minutes per side, until golden brown.
Transfer the chicken to the crock pot.
Whisk together the chicken broth, lemon juice, Dijon mustard, and garlic. Pour over the chicken.
Add the capers.
Place the sliced butter and lemon slices over the chicken.
Cover and cook on LOW for 4–5 hours, until the chicken reaches 165°F and is tender.
Remove the chicken from the crock pot.
Whisk together the cornstarch and water. Stir the slurry into the cooking liquid.
Return the chicken to the crock pot and cook for about 10 minutes, until the sauce thickens.
Serve the chicken and lemon piccata sauce over cooked angel hair pasta.
Garnish with an extra squeeze of lemon juice, parsley, extra capers, fresh cracked black pepper or Parmesan cheese, if desired and enjoy!