Add the olive oil, red wine vinegar, Italian seasoning, salt, pepper and garlic powder to a large ziplock bag. Add the chicken and massage everything around. Refrigerate for two hours or overnight.
*If you're making a freezer meal, stop here and freeze the chicken with the marinade until you're ready to bake the meal.
Preheat the oven to 375 degrees
Remove the chicken from the marinade, shaking off the excess. Discard the marinade, it can not be reused. Pat the skinside with paper towels.
Slice the lemon into wedges. Slice potatoes in half so they are uniform in size. Peel and slice the onions, cutting them into wedges also.
Heat a large skillet over medium heat.
When the skillet is hot place chicken thighs skin side down and saute for about three minutes until the chicken is golden brown. Remove and set on a platter.
Add the potatoes to the skillet. Give the skillet a good shake to coat with the oil from the pan.
Now add the onions and red bell pepper chunks to the skillet. Top with the chicken, placing it skin side up. Tuck the olives and ½ of the lemon slices in wherever they fit.
Place in the preheated oven for 40 minutes. The meal is ready when the chicken registers 165 degrees on an instant read meat thermometer and when the potatoes are fork tender.
If the skin of the chicken doesn't crispy up, tuck it under the broiler for 3-5 minutes until crispy.