For the dressing: Whisk up the Chermoula Sauce with the vinegar and vegetable juice. Store in the refrigerator until ready to serve.
For the taco topping: Char the poblanos over a flame on a gas burners or char under the broiler until the skins are blackened all over. Place the peppers in a bowl. Cover and cool the peppers slightly. Then peel and seed the peppers, and chop. Reserve for later use.
Heat the oil over medium-high to high heat, add the mushrooms and brown a few minutes then add the corn and cook until it starts to brown as well, 5 to 7 minutes more. Add the garlic, onions, oregano, chili powder and some salt and pepper. Cook until the onions are tender crisp, couple of minutes, then deglaze pan with the beer. Add the tomatoes and poblanos, and cook to just heat through. Turn off the heat and cool. Store in the refrigerator for a make-ahead meal. Reheat over medium-high heat until just hot through.
To serve, line a serving platter, bowl or individual shallow bowls with the lettuce and fill with the warmed salad. Top with Tortilla Strips, cheese, peppers and scallions. Pour the dressing evenly over top and serve.
Preheat the oven to 400 degrees F. Cut the tortillas in half and then into thin strips, 1/8- to 1/4-inch thick. Spray lightly with the nonstick cooking spray, then season with salt, and sprinkle with some coriander and cumin. Arrange on baking sheets in a single layer and bake until crisp.