Make the chimichurri sauce by combining parsley, cilantro, oregano, and garlic in a food processor. Pulse until finely chopped but not pureed.
Add olive oil, red wine vinegar, red pepper flakes, salt, and black pepper to the processor. Pulse a few times to combine. Transfer to a bowl and let sit for at least 30 minutes to allow flavors to meld.
Heat butter or olive oil in a large skillet over medium-high heat. Add cauliflower rice and sauté for 6-8 minutes, stirring occasionally, until tender and lightly golden in spots.
Remove cauliflower rice from heat and stir in half of the chimichurri sauce, reserving the rest for serving.
Transfer to a serving dish and drizzle with additional chimichurri sauce. Serve warm or at room temperature.