Season the lamb shanks with the rosemary, thyme, garlic powder, salt, and pepper. Heat a skillet under medium high heat, add about 1 tablespoon olive oil, and brown shanks, about 5 minutes per side.
Set your crockpot to the high setting. Add in lamb shanks. Cover with red wine and beef stock. Add in carrots, parsnips, and onion. Season with salt and pepper to taste. Let cook for about 5-8 hours. (I had mine on the high setting for the first hour and then switched it to low while I was at work).
About 30-45 minutes before serving, add in mushrooms and brussel sprouts. Right before serving, add lemon juice, to taste.
Serve lamb shanks on mixed vegetables that braised along with it in the crock pot.