Classically, tahini dressing is made by mixing it with minced garlic, lemon juice, and water to make a delicious, creamy sauce that is equally good as a sauce for fish or lamb as it is tossed over raw vegetables as a salad dressing.
But the dressing is flexible, and you can really modify it and make it your own depending on how you plan to use it. Blend in a little harissa or chopped jalapeño to add heat and fold it into mashed potatoes for something completely different and unexpected; stir in mint and serve it over a platter of dead-ripe summer tomatoes; mix in lime or sour orange juice instead of lemon, then drizzle the sauce over a complex chopped salad of six or eight fresh and pickled vegetables.
But most of all, I love to use it to dress fresh, warm fish, its residual heat bringing out the sauce's flavors. Fish with tahini is a common dish along the coast of Lebanon, and I like to pair it with another very Lebanese recipe: buttery long-grain basmati with caramelized onions and toasted pine nuts.
For the tahini sauce (about 1 1/4 cups) and the rice:
If you are not using cilantro to garnish the finished dish, then reserve a few sprigs of parsley to instead. Pulse the parsley and garlic together in a food processor and then add the tahini. Blend the garlic, parsley, and tahini well. Add the lemon juice and blend again, the tahini will seize up and become thick. Add a pinch of salt and begin to drizzle water in while the processor is running until the sauce thins out to a pourable consistency. Taste and adjust for salt and lemon juice. Add more of each if needed
Preheat the oven to as hot as it will go, 450 to 500° F. Clarify 4 tablespoons of butter by melting it gently and then removing the foam and reserving the pure fat. To a hot sauté pan, add the olive oil and onion slices with a pinch of salt. Stir quickly and cook over high heat until the onions are brown and caramelized. Drain and reserve. Fry the pine nuts in the clarified butter until they are golden. Drain and reserve. Set a pot of water on to boil and salt. When the water comes to a boil cook the rice in the water for 10 minutes, then drain.
For the fish and the assembly:
While the rice is cooking in the water, rub the flesh of the fish with the olive oil, season it with salt and pepper, and bake in the hot oven. When the rice is cooked and drained, toss it with two tablespoons of butter, the onions, and the pine nuts, reserving a few pine nuts and onions to garnish the fish with.
Place the rice on a platter and top with the fish. Pour about 1/4 to 1/2 cup of tahini over the fish and pass the rest tableside because people will want more. Garnish with some sprigs of cilantro, the reserved onions and the pine nuts, and place the lime slices around the edge of the plate. Serve warm or room temperature