Combine all marinade ingredients in a small bowl. Slice the tempeh burger and add to skewers. Brush with the marinade and let it set for at least 15 minutes.
In the meantime, cook the potatoes and steam/grill the corn on the cob. Mash the potatoes to your desired texture, mix in the vegan butter (whilst still warm), and season with nutmeg, salt and pepper. Adjust the texture with 2-3 Tbsp plant milk.
Cook the tempeh until crispy and caramelised on both sides, brushing with more sauce while cooking. You can BBQ, pan-fry, oven grill or bake the tempeh.
Serve the tempeh ribs with mash and corn, and drizzle any leftover sauce on top.