Arrange tofu in a single layer in the dish and set aside.
Place juniper in the mortar and crush. Transfer half to the saucepan, then add the peppercorns to the mortar and crush. Set aside.
Add everything else to the saucepan and bring to a boil. Let cool.
Pour the cooled marinade over the tofu and turn each piece to coat. Let sit for at least 2 hours, turning the tofu every 30 minutes so that both sides spend equal time submerged.
Preheat broiler to 500.
Shake off excess marinade and transfer the tofu to the cookie sheets. Sprinkle the juniper-pepper mixture evenly on top of each piece.
Broil until golden brown, 3-4 minutes.