I'm told that there are certain types of people in this world—perhaps even sharing a roof with me—who gain immense pleasure out of discovering that a pair of shoes they bought to fit with one outfit works perfectly with another, or perhaps that the tie they bought for their suit looks great on their new shirt. This is somewhat baffling to me, but I gather it's a joy similar to what I feel when I discover that a condiment or seasoning I designed for one dish works swimmingly with a completely different one.
The big ol' batch of red curry paste I had in my fridge was something I'd originally made for my phat phrik khing recipe, but there's only so much stir-fried green beans and tofu one can eat. So the other night, when my wife, Adri, suggested that we have fish for supper (a suggestion she made while wearing a smashingly coordinated pair of shoes), my first thought was: How can I use that stuff up?
It turned out to be even easier than I'd imagined: Give it not one but two new uses, both as a marinade and as the base for a sauce.
For the marinade portion, I knew that simply rubbing it on the halibut fillets I'd picked up would cause issues with sticking down the line when they hit the grill. So I added just a touch of olive oil to the paste in order to help it release better.
I then took some additional curry paste, added a big glug of extra-virgin olive oil to it, and whisked it together with some lime juice and fresh mint and cilantro, transforming it into a chunky vinaigrette.
Then it was out to the grill.
Fish can be a little tricky on the grill, especially skinless, flaky fish like halibut. If it sticks even a little bit, it'll tend to fall apart when you try to flip it. There are a few tricks to getting around this. The first is to make sure that your grill grates are properly heated and cleaned. I let mine preheat for a full 10 minutes before giving them a good scrub-down with a grill brush.
Second, make sure the grates are oiled. I add several coats of oil—up to a half dozen! Just like seasoning a cast iron pan, brushing oil on in multiple coats will help build up a nice nonstick surface on your grill grates. Third, don't move the fish until it's ready to be released. Prematurely prodding and poking at it will only make it more prone to breaking. When it's ready to be flipped, you should be able to pry it up with a thin metal spatula with almost no effort.
One more tip: If you do happen to scar your fish, don't sweat it too much. There's nothing a little sauce can't hide. In fact, one of the pieces of fish in this photo was severely damaged when I flipped it (that's what happens when you try to photograph and cook at the same time). I just pushed it back together, spread a little of the curry vinaigrette over it, and nobody was the wiser.
A few minutes on each side, and dinner is ready. I couldn't resist throwing some asparagus onto that grill and dipping it into the same vinaigrette. It was delightful.
I love halibut on the grill because it has the thick, meaty bite of a larger finfish, but the flakiness and mild flavor of bottom-feeders. Like cod, hake, and other flaky white fish, it quickly goes from moist to dry and tough, so make sure not to overcook it. An instant-read thermometer will help with this task—140°F is what you should aim for. If you don't have one, take a thin metal skewer or cake tester and poke it into the flesh. If the fish is still undercooked, you'll feel a little resistance as the skewer breaks through the membrane between each muscle layer. As soon as the fish is perfectly cooked, the skewer should slide in and out smoothly.
If you happen to have homemade red curry paste (or a good store-bought brand) kicking around your fridge already, go ahead and use it. Otherwise, the recipe linked to here has full instructions for how to make a quick and easy red curry paste from scratch, just for this dish. It's sort of like custom-cobbling your own shoes, but a little tastier.