In a medium bowl, whisk all marinade ingredients together.
Place tempeh in 9 x 12 casserole dish and cover with marinade. Marinate tempeh for 30 minutes or overnight (overnight is best to infuse the flavor into the tempeh). Strain marinade, save for the gravy.
Preheat oven to 375 degrees F. Place casserole dish with marinated tempeh into the oven for 45 minutes, turning tempeh after 20 minutes.
Using a large fry pan melt vegan butter over medium-high heat. Add tempeh to pan and brown on both sides about 5-10 minutes. Pour in a little liquid while cooking if needed. Remove and set aside.
Using the same fry pan make the gravy. To release the tempeh brown bits add in a little wine or broth. Now add in strained marinade and broth. Using either a bowl or mason jar add flour to milk and shake or stir until smooth. Slowly stir in plant-based milk and flour to the pan and bring to a rolling boil until it thickens. Taste, add salt, pepper and additional herbs if needed.
Place warm tempeh on serving dish and top with gravy and fresh herbs.Serve immediately.