If using a raw beet, roast it wrapped in foil at 400°F for ~40 minutes until tender. Let cool, peel, and slice.
1 small beet
In a small bowl add, blackberries, blueberries, arugula, goat cheese, walnuts, mint and red onion.
¼ cup blackberries, ¼ cup blueberries, 1 cup arugula, 1 tbsp goat cheese, 1 tbsp walnuts, 1 tsp mint, 2 tsp red onion
In a separate bowl whisk together olive oil, balsamic, Dijon, salt and pepper until emulsified.
1½ tsp olive oil, 1 tsp balsamic vinegar, ½ tsp Dijon mustard, 1 pinch salt, 1 pinch pepper
Drizzle dressing over top and gently toss.