Cooking fish doesn’t need to be intimidating. In fact, few things could be simpler—or more rewarding. For meaty steaks of swordfish, albacore, and halibut, all you need is a kiss of high heat from a grill or cast-iron pan and a simple vinaigrette. Zesting citrus directly onto your food means no wasted precious aromatic oils and zero chance of the zest drying out before you use it.
Prepare a grill for medium heat; oil grates. Finely grate 1 tsp. lemon zest directly onto halibut and lightly drizzle with oil; season with salt and pepper. Grill halibut, turning once, until browned on both sides and just opaque in the center, about 5 minutes.
Meanwhile, combine tomatoes, hearts of palm, and ¼ cup oil in a medium bowl; squeeze in 2 Tbsp. juice from lemon and toss to combine. Season with salt and pepper.
Toss basil into tomato salad. Serve halibut with tomatoes and dressing spooned over.