In a large bowl, season the chicken thighs with olive oil, salt, black pepper, and Italian seasoning. Toss to coat evenly.
Place the seasoned chicken in the CrockPot. Add the minced garlic, cherry tomatoes, and baby spinach on top of the chicken.
Pour the heavy cream over the chicken and vegetables, then sprinkle the grated Parmesan cheese on top.
Cover and cook on low for 6-7 hours or on high for 3-4 hours, until the chicken is tender and cooked through.
Once cooked, stir the mixture gently to combine the sauce with the chicken and vegetables.
Garnish with fresh basil before serving. Serve over pasta, rice, or with crusty bread to soak up the sauce.