Next add the sliced mushrooms to the skillet. Saute, stirring occasionally, until most of the liquid from the mushrooms has evaporated and the mushrooms are soft. Season to taste with salt and pepper.
Meanwhile, prepare the Chimichurri by adding the parsley, oregano, garlic, red pepper flakes, red wine vinegar, and salt and pepper to the bowl of a food processor. Pulse, scraping down the sides of the bowl as needed.
Stream the olive oil through the funnel in the top while the food processor is running. Taste and adjust the seasonings, if needed.
Build the tacos by adding some of the mushrooms to each tortilla then topping with Chimichurri. Garnish with avocado slices, if desired, and enjoy!
Nutrition Facts do not include the optional avocado slices.To keep your tortilla warm for up to an hour, I recommend this inexpensive insulated Tortilla Warmer.Any leftover Chimichurri will last refrigerated for 1-2 days. Mix well before serving since the olive oil will solidify.