Preheat the oven to 150°C (300°F). Line a baking sheet with a silicone mat.

In a bowl, sift together almond flour and powdered sugar.

In a separate bowl, whip the egg whites with salt until soft peaks form. Gradually add granulated sugar and continue to whip until stiff peaks form.

Gently fold the beet puree into the meringue, then fold in the almond flour mixture until just combined.

Transfer the mixture to a piping bag and pipe small circles onto the prepared baking sheet.

Let the macarons sit at room temperature for 30 minutes to form a skin.

Bake for 15 minutes, then cool completely.

In a bowl, combine softened goat cheese, chopped walnuts, honey, thyme, and black pepper. Mix until smooth.

Pair the macaron shells by size. Pipe a dollop of filling onto the flat side of one shell and top with another shell.

Refrigerate for at least 30 minutes before serving to allow flavors to meld.