Dice onion and bell pepper. Mince garlic cloves.
Chop skinless yukon gold potatoes into bite-sized pieces (about 3/4 inch in size). Set aside.
In a large pot, heat olive oil until shimmering. Add chicken and cook, undisturbed, for 4-5 minutes until browned on that side. Turn and cook for another 4-5 minutes. Don't throw away the marinade!
Remove chicken from pot and place on a plate. Turn down the heat if necessary. Add diced onion to the pot and cook for a minute or so. Stir occasionally until just beginning to turn translucent.
Add diced bell pepper and garlic and cook for another 2-3 minutes, stirring often.
Add vino seco, chicken broth, tomato sauce and leftover marinade to the pot. Stir in oregano, cumin, ground pepper and bay leaf. Put the chicken back in the pot and add potatoes.
Simmer, partially covered, for 40 minutes. Stir occasionally.
After 40 minutes, add balsamic vinegar and olives. Remove lid and simmer for another 20 minutes.
Remove the pot from the heat. There are two choices for serving the chicken. You may either shred the meat from the bones now and stir into the stew; or you may serve each person an intact drumstick with the soup ladled around it. Serve with white rice if desired.