Add 1 tablespoon olive oil to a large skillet and place over high heat. Add chicken pieces and generously season with salt and pepper, browning the meat for about 5-6 minutes. Transfer to a large 6 or 8-quart slow cooker.

In the slow cooker, add chicken broth, dry white wine, worcestershire sauce, balsamic vinegar, thyme, rosemary, dried oregano, and additional salt and pepper. Stir until combined, then add garlic, onion chunks, carrots, and diced potatoes.

Cover and cook on low for 7-8 hours or on high for 4-5 hours.

Remove ½ cup of broth from the slow cooker and transfer to a medium bowl. Stir in ½ cup of milk and whisk in ¼ cup flour until smooth. Add the mixture back to the slow cooker and stir to combine.

Stir in frozen peas and cook uncovered on high for 15-20 more minutes until the stew thickens. Taste and adjust seasoning, if necessary. Serve immediately.