1. Bring a large pot of water to boil over high heat and season with salt to make it salty like the sea.

2. Cut the kohlrabi bulb away from the stems, and cut the bottom of the stems from the leaves, separating the bulbs, stems, and leaves.

3. Fill a large bowl with cold water; set aside. Add the leaves to the pot of boiling water and blanch for 30 seconds. Using tongs or a spider, transfer the leaves to the bowl of cold water. When cool, spin the leaves dry in a salad spinner. Coarsely chop and reserve.

4. Add the stems to the boiling water and cook until soft but not mushy, about 15 minutes. Using tongs or a spider, transfer to a clean work surface to cool. When cool enough to handle, cut stems into 1-inch pieces.

5. Using a vegetable peeler, remove the tough outer skin of the bulbs. Cut half the bulbs into ½-inch dice and the other half into thin rounds using a knife or mandoline.

6. In a small skillet, heat 2 tablespoons olive oil over medium heat. Add the diced kohlrabi and the cooked stems. Sauté until slightly softened and golden brown in spots, about 7 minutes. Season to taste with salt and pepper. Remove from the heat and let cool.

7. For the pesto: In a food processor bowl, combine the walnuts, garlic, and ½ teaspoon salt. Process until a thick paste forms. Add the chopped kohlrabi leaves and lemon juice, and process until the mixture is finely chopped. Gradually add ½ cup olive oil and process the pesto (mixture may not be completely smooth).

8. For the salad: In a serving bowl, combine the raw sliced kohlrabi and the cooked diced kohlrabi and stems. Season with salt and pepper to taste, then add half the pesto (about ½ cup). Toss and serve.