In a bowl, and mix all ingredients for Chicken Marinade except chicken to make a marinade. Add chicken breasts to the bowl with marinate. Use tong to coat chicken in marinade. Cover and let marinate for at-least 30 minutes (up-to overnight).

Heat 2 tsp oil in a wide heavy bottom skillet. Once skillet is very hot, place marinated chicken breasts in the skillet in one single layer. Once bottom side is no longer pink and is golden caramelized (in about 2-3 minutes), flip chicken top side down to sear other side.

Transfer cooked chicken into a plate and set aside. In now empty skillet (heat on, don't clean skillet), add remaining olive oil. Add sliced onions, sugar with a pinch of salt and pepper. Cook stirring 2-3 times until onions are slightly caramelized. (about 8 minutes). Stir in Worcestershire sauce in last one minute.

Once Onion are soft and slightly caramelized, these will pick all chicken flavor from the skillet. Add white wine, stir to loosen bits of chicken marinade attached to the skillet, and cook until liquid is reduced to half. (2-3 minutes)

Add chicken stock, cream. Mix with onions. Return seared chicken along with juices on to the top of the onion-cream mixture. Cover pan with lid and simmer on medium heat for 8-10 minutes or until chicken is fully cooked and sauce has thickened.

Taste and adjust salt or pepper. Serve chicken pieces on the bed of caramelized onions cream sauce. Garnish with fresh herbs. Pasta or a crunch salad works great on side.