Shred the kohlrabi, carrots and garlic in a food processor fitted with the shredder attachment.
Heat the olive oil in a large skillet over high heat. Add the tomatoes, followed by the shredded vegetables. Saute for 3 to 5 minutes. Season with salt and pepper, and then add the scallions, parsley and lemon juice, stirring until incorporated. Simmer for 10 to 15 minutes.