1. Preheat slow cooker to high heat. (If yours doesn’t sauté, do this step in a deep saucepan on the stove.) Add oil and onion and sauté until translucent, around three to four minutes.
2. Add meat and sear on all sides until browned but not cooked through.
3. Add garlic and sauté for one minute.
4. Pour in wine.
5. If using a saucepan on the stove, lower flame to medium-low for around five minutes, then transfer everything to the slow cooker.
6. Add the rest of the ingredients. Cook on high for five hours or low for six to eight hours.