Preheat oven to 350 degrees. Place the walnuts on a cookie sheet pan and roast for 5 minutes or until fragrant. Remove from oven and cool. Increase oven temperature to 375 degrees.
Place the beets on a large piece of foil. If the beets are large, cut them into halves. Do not peel the beets. Drizzle with 2 teaspoons of olive oil. Bring the foil up around the beets to encase them. Place the foil packet on a cookie sheet pan. Roast the beets until a paring knife easily goes through them. Depending on the size of the beets, this will take 35 to 45 minutes.
Remove and let cool to the touch. Place the beets under slow running cold water and remove the beet skin. If needed, use a paring knife to help remove the skin. Rough cut the beets.
Place the beets, toasted walnuts, cheese, balsamic vinegar, fresh herbs and garlic cloves in the food processor. Pulse to combine. With the food processor running, slowly add the remaining ¼ cup olive oil until pesto is a consistency that is spreadable. Season with salt and white pepper. Makes approximately 2 cups of pesto.
Place the 1 cup of flour, salt and baking powder in the bowl of a food processor fitted with a steel blade. Pulse briefly to combine. Add the yogurt and pulse. With the processor running, slowly add the water through the feed tube. The dough should come together and not be sticky. If it is sticky, pulse in a little more flour.
Place the dough on a work area and knead for 2 minutes. Divide dough into 6 equal size pieces. Dust work area with cornmeal and roll the dough out into 5-inch rounds.
Heat a grill pan or heavy sauté pan on medium high heat. Do not add oil. When hot, place one or two of the flatbreads (depending on the size of pan). When bottom side is lightly brown and top begins to bubble, carefully flip the bread and cook on the other side. Total cooking time will be about 4-to-5 minutes. Repeat with remaining dough rounds.
Spread the beet pesto on top of the warm flatbread. Top with soft goat cheese. Garnish with fresh sage leaves. If desired, flash under a hot broiler to toast the top of the cheese and frizzle the sage leaves.