When you brown butter, as in this recipe, the flavor intensifies so adding just a little to Brussels sprouts still makes a big impact.
Bring 1 inch of water to a boil in a large saucepan fitted with a steamer basket. Add Brussels sprouts, cover and steam until tender, 5 to 7 minutes.
Meanwhile, melt butter in a small skillet over medium heat. Cook, swirling often, until the butter turns a nutty brown, 1 to 3 minutes. Stir in oil and scrape into a large bowl with a rubber spatula. Add the Brussels sprouts, almonds, vinegar, dill, salt and pepper and toss to combine.
Tip: To toast slivered almonds, place in a small dry skillet and cook over medium-low heat, stirring constantly, until fragrant and lightly browned, 2 to 4 minutes.