20 grams kombu pieces
2.2 liters cold water, preferably soft water
100 grams bonito shavings
4 tablespoons Strauss unsalted butter
High quality Japanese white soy sauce
4 purple or green baby kohlrabi
1 large daikon
24 baby turnips
2 handfuls flowering broccoli rabes, shoots, leaves, stems and flowers still attached
2 handfuls wild radish rabes or other spicy flowering rabes
Fleur de sel
To Assemble and Serve:
1 Meyer lemon
Handful seasonal edible flowers, such as nasturtium, herb flowers
For the Bonito Broth:
Gently wipe the kombu to remove any residue. Submerge in the cool water and let soak for 40 minutes. Place the kombu in a saucepan over a medium heat, and bring to 180ºF, or until small bubbles form on the bottom of the pot. Remove the kombu and discard. Warm the remaining liquid over low heat, add the bonito shavings, and let infuse for 15 minutes until the flavor of the bonito is prevalent and the broth has a smooth mouthfeel. When the bonito tastes at its peak, strain though a fine-mesh sieve.
For the Vegetables:
Rinse the vegetables in cold water to remove any dirt. Peel the kohlrabi, daikon, and turnips then submerge in cold water to cover. Cut all peeled vegetables into 1½-inch obliques or roughly the same size as the peeled turnips for even cooking. Remove the vegetables from the water, then cook one variety at a time over low heat with a little broth, in a covered Le Creuset or stainless steel pot, until just tender. Remove each vegetable when done and set aside until entire batch is complete. Repeat the process with all the other vegetables except the rabes. Once complete, add all of the just-cooked vegetables to a pot with the remaining cooking broths, bonito broth, and butter just to cover. Season sparingly with the white soy. Warm gently until all the vegetables are hot.
Heat a stainless steel pan over medium heat, with some olive oil. When the pan is hot, add the rabes and do not move. Lower the heat to low and season with fleur de sel. When the rabes are golden and crisp on one side, gently turn over and cook until just done, roughly 1 minute. Set aside.
To Assemble and Serve:
Mix the vegetables evenly with the butter. Pour the vegetables into a bowl with the broth coming halfway up the vegetables. Place the caramelized rabes on top and season with a few drops of Meyer lemon juice. Garnish with seasonal flower petals.