In this dish, the lime juice melts the seasoning paste you've cooked the fish with and gives the halibut a glaze that looks like lacquer. And I like to think of the eggplant as a gentle pillow for the fish to lie down on. There's a big advantage to cooking halibut, which doesn't have a lot of fat, on the bone. It helps keep the fish moist and juicy. And since it's just one big bone, it's easy to pull off; there are no pin bones to worry anyone.
- Set a rack in the middle of the oven and preheat the broiler. Lightly crumple a piece of aluminum foil (it will keep the eggplant from rolling) and set it on a small baking sheet.
- Rub the eggplant with olive oil and set it on the foil. Slide the pan into the oven and broil the eggplant, turning it several times, until the skin is charred and split in spots and the flesh feels soft, 15 to 20 minutes. Cool on a cutting board.
- Meanwhile, heat a small cast-iron skillet over medium-high heat. Char the jalapeño and garlic until the chile is blistered or charred all over and the garlic is browned in spots, about 10 minutes. Cool on the cutting board.
- When the vegetables are cool enough to handle, peel the eggplant, cut it into chunks and put it in a food processor. Stem, seed, and chop the jalapeño and add it to the processor. Peel the garlic and add to the processor. Spoon in 2 tablespoons olive oil and puree.
- Heat a skillet over high heat. Add the water and spinach and cook, tossing with tongs, until the spinach wilts, 30 seconds to 1 minute. Turn off the heat, stir in the eggplant puree, and taste for salt and pepper.
- Mix 2 tablespoons of the olive oil, the ketjap manis, minced garlic, and dill in a small bowl to make a seasoning sauce.
- Heat the remaining 1 teaspoon olive oil in a nonstick skillet over medium heat. When it's hot, brush the halibut liberally with the seasoning sauce and add to the skillet. Cook for 4 minutes. Turn the fish over and add the butter to the skillet. Cook, basting often, for another 4 minutes. Add the lime juice and cook, basting constantly, for another minute.
- Divide the eggplant and spinach between two dinner plates. Top with a piece of halibut steak and serve.