Prepare and marinate the tempeh. Place the blocks of tempeh in a saucepan and cover with water. Bring to a boil, then reduce heat and simmer for 10 minutes to remove bitterness. Drain well. Once cool enough to handle, slice each tempeh block into 8 thin strips. In a shallow dish, whisk together vegetable broth, soy sauce, apple cider vinegar, maple syrup, smoked paprika, 1 tsp garlic powder, 1 tsp onion powder, and caraway seeds. Place the sliced tempeh in the marinade, ensuring all pieces are coated. Let it marinate for at least 30 minutes, or up to 4 hours in the fridge.