Roasted Beets With Fennel and Bonito Dressing

Preheat oven to 425 °F. Toss beets with 1 Tbsp. oil in an 8x8" baking dish; season with salt. Add 1/4 cup water and cover tightly with foil. Roast beets, shaking once, until a knife slips easily through flesh, 60 –75 minutes. Let cool slightly, then rub off skins with paper towels. Using 2 forks, tear beets into large pieces; toss in a large bowl with 2 Tbsp. oil. Meanwhile, toast aniseed in a small saucepan over medium heat, tossing often until fragrant, about 3 minutes. Add vinegar, sugar, 2 tsp. salt, and 1 cup water. Increase heat to medium-high and bring to a simmer, stirring to dissolve sugar and salt, about 4 minutes. Remove from heat and let steep 20 minutes. Place fennel in a small bowl and strain brine over. Cover and chill until cold, about 2 hours. Cook garlic, butter, and 1/4 cup oil in a small saucepan over medium, stirring occasionally, until garlic is soft but not brown, about 2 minutes. Stir in bonito flakes and transfer to a blender. Purée until only a few flecks of bonito remain. Prepare a grill for medium heat. Grill beets, turning occasionally, until lightly charred, about 5 minutes. Transfer back to bowl; toss with bonito dressing and lemon juice and season with salt. Toss arugula and remaining 1 Tbsp. oil in a medium bowl; season with salt. Grill until lightly charred in spots, about 30 seconds. Transfer back to bowl. Arrange beets on a platter and top with arugula and drained pickled fennel.