Very thinly slice kohlrabi with slicer or preferred method.
Whisk together lime zest and juice, 2 tablespoons oil, and 1/2 teaspoon each of salt and pepper in a large bowl. Toss kohlrabi with dressing.
Finely chop kale. Heat remaining 2 tablespoons oil in a 12-inch heavy skillet over medium-high heat until it shimmers. Sauté garlic until pale golden, about 30 seconds. Add kale by the handful, turning and stirring with tongs and adding more kale as volume in skillet reduces. When all of kale is wilted, sauté with 1/2 teaspoon salt until just tender, about 3 minutes. Transfer to a bowl and cool to room temperature. Toss kale with kohlrabi and pistachios.
