For the dough, combine all ingredients plus 1 cup (240 ml) water in the bowl of a stand mixer fitted with the paddle attachment and mix on low speed until the dough just comes together, 1 to 2 minutes, adding more water, a tablespoon at a time, if needed. Switch to the dough hook attach-ment and mix on low speed until the dough is very smooth and soft, 5 to 7 minutes. (Alternatively, you can mix and knead the dough by hand: In a large bowl, stir the ingredients until they come together, then turn out the dough onto a lightly flouåred surface and knead until the dough is very smooth and soft, 10 to 15 minutes.) Cover the dough and allow it to rise at room temperature out of direct sunlight for 1 hour.
Meanwhile, for the bianca sauce, in the bowl of a stand mixer fitted with the paddle attachment, combine the yogurt, ricotta, cream cheese, garlic, lemon zest, salt, dill, and pepper and mix on medium-low speed until smooth. Cover and refrigerate until ready to use.
Divide the dough into two equal balls and shape them into flat circles, about 10 to 12 inches (25 to 30.5 cm) in diameter. Place each one on a sheet of parchment paper. Cover with a lightly greased sheet of plastic wrap and allow to rise at room temperature out of direct sunlight for 30 minutes.
Preheat the oven to 500°F (260°C) with a baking stone inside of it. Alternately, you can cook the pizza on a metal round pizza pan.
For the toppings, cut the bottom third off the asparagus spears and dis-card them, reserving the top two-thirds. Cut the stalks into 1-inch (2.5-cm) pieces and toss them with the oil and ¼ teaspoon of the salt.
Pat down the centers of the raised pizzas to flatten slightly, leaving a 1-inch (2.5-cm) crust border around the edge that is slightly elevated. Spread the bianca sauce on the center of each of the two pizzas, leaving a 1-inch (2.5-cm) border for the crust. Sprinkle half the Parmesan on each of the pizzas, and evenly distribute the asparagus between the two pizzas.
Bake the pizzas one at a time. To transfer the pizza onto the baking stone, keep the pizza on the parchment paper and put it on a flat surface like a large cutting board. Open the oven and hold the cutting board next to the baking stone, using your other hand to pull the parchment paper off the cutting board and onto the baking stone. Close the oven and bake until the crust is deeply golden and the tops of the Parmesan shavings begin to turn gold, 12 to 15 minutes. Repeat with the second pizza.
Top the pizzas evenly with the arugula, kohlrabi, and chives. Give the lemon half one good squeeze above each of the pizzas, moving it in a small circle as you do to distribute the juice evenly. Evenly distribute the remaining ½ teaspoon salt and the pepper between the two pizzas and serve.