Place your chicken breast on a cutting board and cover in plastic wrap. Using a mallet, pound the chicken starting at the thickest part until the chicken is even and 1 inch thick. Season the chicken with salt, pepper, oregano, and basil. Use as much season as you need to evenly coat the chicken and feel free to use any other savory spices you like to cook with.
Heat the olive oil in a large pan or skillet over medium-high heat and cook the chicken on on both side until nicely brown. The chicken should be thoroughly cooked. Remove the chicken from the plan and place on a plate, set aside.
Add in the sliced onions and sauté until translucent, tender, and fragrant. Add in the butter and garlic and sauté for another 3-4 minutes. Pour in the water and deglaze the pan as needed. Add in the brown sugar and Herbes de Provence and stir well. Pour in the balsamic vinegar and heavy cream and bring everything to a boil. Once you reach a boil add the chicken back into the plan and reduce the heat to low and let simmer for 5-7 minutes before removing from the heat. Enjoy!