Heat oil in large skillet.
Salt and pepper turkey, and let sit for 10 minutes.
add fresh veggies and spices/herbs to oil and saute for 5 minutes over med-high heat to caramelize. Remove to crockpot.
Add turkey and brown on all sides. Remove to crockpot.
deglaze pan with 1/2 cup wine and 1 cup water. Add to crock pot. Add rest of wine and cook on low for 8-10 hours.
Remove turkey and set aside to cool. Strain liquid, and discard vegetables.
Heat oil in skillet and toss onions to brown. Reduce heat, remove onions and add liquid and reduce for 10-15 minutes until syrupy.
Meanwhile, preheat broiler, slice polenta, and brush pan and polenta with oil. Broil on both sides for 5-7 minutes until crispy.
While polenta is broiling, remove turkey off the bone and add in large pieces to reduced liquid. Add onions and simmer until heated through.
Serve turkey and sauce over polenta.