Heat olive oil in a skillet over medium-high heat. Add the seasoned chicken breasts to the hot oil and cook for 3 minutes per side or until just browned. Transfer chicken to slow cooker and top with mushrooms and garlic.

Return skillet over medium-high heat and add the chicken broth; cook for 1 minute, scraping up all the browned bits from the bottom of the skillet. Pour the broth over the chicken and mushrooms.

Close with a lid and cook on LOW for 4 to 5 hours, or on HIGH for 2 to 3 hours. Chicken is done when internal temperature reaches 165˚F.

Remove chicken breasts from slow cooker and set aside on a plate.

Combine water and cornstarch in a mug or a small mixing bowl and whisk until incorporated; then, whisk the slurry into the wine sauce.

Add heavy cream to the wine sauce and whisk until combined. Taste for salt and pepper, and adjust accordingly.

Return chicken to the slow cooker; cover with a lid and cook on HIGH for 20 minutes or until sauce has thickened. For a creamier texture, add more heavy cream.

Transfer chicken from slow cooker to plates; top with mushroom sauce and garnish with fresh parsley. Serve.