In a large skillet, heat the olive oil and sauté the diced onion, carrots, and minced garlic for about 5 minutes. Add the celery and sauté for another 3 minutes.
Transfer the sauteed vegetables to a large (~6-quart) slow cooker. Add the next 7 ingredients (mushrooms through dried thyme) and stir well. Cover and cook on the low temperature setting for 5 hours.
Carefully taste and season with salt and pepper, if desired. Stir in fresh parsley and serve hot.
Notes
You can use any kind of smoked meats you like - sausages, chunks of smoked pork shoulder, cooked bacon, smoked chicken legs, etc. 1-2 lb of meat is a good amount for this stew!
You will need a large slow cooker. A 6-quart one works great!
You can substitute diced leeks for onions. Thoroughly wash the diced leeks to remove any dirt.