In a large skillet, heat olive oil over medium-high heat. Salt and pepper chicken. Brown in hot skillet on both sides. Transfer to slow cooker. Add butter, white wine, juice and zest of lemon, and caper berries. Cover and cook on low for 5-6 hours. Or on high 3-4 hours.
Whisk cornstarch into chicken broth, then whisk mixture into crockpot. Add tomatoes. Cover and cook on high for 20 minutes or so, just until the mixture begins to thicken.
Serve over zucchini noodles. Salt and pepper to taste.