Fish Doneness Test for Packets:
**When parchment starts to brown and puff, the fish should be done. Double-check using one of these methods: Skewer: Before cooking, poke a wooden skewer into a fillet so you can feel the resistance of the raw fish. After 10 minutes baking, poke a skewer into a fillet through the packet. The skewer should have little to no resistance. Fork: Carefully unfold one side of a packet. The fish should just flake when tested with a fork. Rewrap to serve. Thermometer: Insert a thermometer into fish through the packet; it should register 145°F to 155°F.
Flavor variations
If desired, add 2 Tbsp. coarsely chopped roasted peanuts to the gremolata and 1/2 tsp. curry powder, garam masala, or berbere spice to the olive oil, coconut oil, or melted butter.
