Preheat the oven to 400°F (200°C).
Wash and remove the leaves from the beets. Cut them in small cubes.
Toss the beet cubes in 2 tablespoons of olive oil and spread them onto a baking tray. Roast in the oven for 40 minutes, or until they are tender.
While the beets are roasting, toast the walnuts in a small pan over medium heat for 5-6 minutes. Let them cool down.
Once cool, add the walnuts to a food processor or blender and pulse until finely chopped.
Add the roasted beets, minced garlic, Greek yogurt, lemon juice, and remaining 2 tablespoons of olive oil to the food processor or blender. Blend until smooth.
Season with salt and pepper, to taste.
Serve in a bowl and garnish with fresh herbs, if desired.
Serve with your favorite chips, vegetables, or crackers.