1. Bring the beetroots to a boil over medium heat in a large pot of lightly salted water. Simmer for about 35-40 minutes, or until fork tender. Remove, drain, and rinse. Peel the beet roots and cut into 1-inch (2/5 cm) cubes.

2. While the beetroots are boiling, toss the walnuts in a nonstick skillet over medium heat until lightly toasted. Remove, set aside to cool slightly and chop or pulverize in a food processor until coarsely ground.

3. In a medium bowl, whisk together the olive oil, vinegar, yogurt, and garlic. Add a little salt to taste. Whisking all the while, dilute the dressing with about 2-3 tablespoons of water. Mix in the walnuts.

4. Pour the dressing over the beets, adjust seasoning with salt and serve. The salad may be served either at room temperature or chilled.