Preheat oven to 425ºF. Trim ends off 2 squash and cut in half lengthwise; scrape and discard seeds from the center of each half. Slice into ½-inch-thick half-moons; transfer to a large rimmed baking sheet.
Whisk 2 tablespoons each melted butter and miso and ½ teaspoon garlic together in a small bowl until thoroughly combined; dollop over the squash and toss with your hands until all sides are evenly coated. Arrange in an even layer. Roast, flipping once, until tender and browned in spots, 15 to 20 minutes.
Drizzle the squash with 2 teaspoons lemon juice; stir gently to coat. Transfer to a platter; top with ¼ cup almonds and 2 tablespoons dill.
