Prep the romaine by pulling off any lingering leaves on the outer edges. If you hold the lettuce head upright these leaves tend to naturally fall. Cut the romaine in half lengthwise. It's okay if some outer layers fall off during this process. You want the piece that you grill to be sturdy.
Use a silicone brush or your fingers to rub oil over the cut side of each lettuce half. Sprinkle with salt and pepper and use your hands to make sure the oil and seasoning gets into the grooves of the lettuce.
Once the lettuce is prepped, get the sourdough ready. Slice the sourdough into triangles (see photo above). Brush each piece with olive oil and sprinkle the pieces with garlic powder, salt, and pepper.
Before grilling, prepare the dressing. Combine all of the ingredients for the vegan caesar dressing together in a high speed blender or food processor. Blend for about a minute, or until smooth and creamy.
Before turning on the grill, use a wadded up paper towel and tongs to brush olive oil onto the grates. Be careful to not use too much oil or else it will drip down and cause some larger flames.
Turn on the grill and bring the heat to medium. As you grill, keep an eye on the temperature trying not to exceed 500 degrees. I kept my grill right around 450. If it gets too hot you can always turn off the middle knob.
When ready, place the romaine lettuce cut side down onto the grates using tongs. Grill for about 3 minutes or until the desired texture is achieved.
If there's room toss the sourdough pieces on at the same time, using the tongs to press each piece firmly into the grill so you get that nice marking on each piece of bread. Grill the bread for 3-5 minutes, or until desired texture.
Place the finished romaine halves on a tray cut side facing up. Use a spoon to rub the caesar dressing onto each piece, getting into the grooves. Take the block of vegan parmesan and grate some cheese on top. Serve alongside the tray of sourdough.