Cook Morningstar Farms® America's Original Veggie Dogs® according to package directions. Meanwhile, wrap buns in microwave-safe paper towels. Micro-cook on high for 10 to 15 seconds or until warm. Place one veggie dog and two tomato pieces in each bun. Squeeze mustard in zig-zag pattern on top. Top with relish and onion. Arrange two peppers and one pickle spear in each bun. Lightly sprinkle with celery salt. Serve immediately.