Start your steaming apparatus.
If your tempeh is a rectangle: slice it into 2 squares. Slice those squares into two thin squares across the middle, sort of like a clamshell. Now slice each square corner to corner, into triangles. You should have 8 thin triangles.
If your tempeh is square: slice in half into two rectangles. Slice each rectangle across the middle, sort of like a clamshell. Then slice in half, into squares. You should have 8 thin squares.
Steam the tempeh for 10 minutes. It’s going to smell like baking bread!
In the meantime, mix all mariande ingredients together in a big bowl. When tempeh is ready, transfer it directly into the marinade.
Let marinate for 1 to 4 hours, flipping occasionally.