Heat a small, dry skillet over medium-low heat. Add the sliced almonds and toast for 2 to 3 minutes, stirring constantly, until fragrant and lightly golden. Immediately transfer to a small plate to stop the cooking; set aside, reserving a small handful for garnish.
Add the olive oil, lemon juice, dill, Dijon, sea salt, and pepper to a glass jar. Seal tightly and shake until the dressing is fully emulsified.
Using a mandoline set to its thinnest setting (or a very sharp chef’s knife), slice the beetroots and fennel bulb paper-thin. Place them into a large mixing bowl.
Pour the dressing over the vegetables and toss thoroughly to coat. Let the salad sit for 10 to 15 minutes before serving.
Note: The acid in the lemon juice will draw out the beetroot juices, marinating the fennel into a vibrant pink hue and slightly softening the raw crunch.
Just before serving, toss in the main batch of almonds. Transfer to a shallow serving bowl and top with the reserved almonds and fresh dill leaves.
Chef's Tips
Slicing the beets paper-thin on a mandoline is crucial. Raw beets have an incredible, refreshing crunch when shaved thin, but are too dense if cut into thick chunks.
Always add the toasted almonds at the absolute last second before serving. This keeps them stark white and perfectly crunchy against the pink salad backdrop.