1. Pre-heat oven to 375º.
2. In a medium bowl combine the marmalade, orange juice, vinegar, zest and Tuscan seasoning. Set aside.
3. Season chicken with kosher salt and pepper on both sides.
4. Bring a 12" cast iron skillet or non-stick oven safe saute pan over medium high heat, add oil and place chicken breasts skin side down.
5. Cook for 5-7 minutes or until skin is golden and crispy, then flip chicken.
6. Brush the crispy chicken with 3/4 of the orange glaze. Pour the stock around chicken, add butter and bake for 10-14 minutes or until internal temperature reaches 160º.
7. Brush cooked chicken with remaining glaze. Server warm,