1. Take the stems out of the mushrooms, and brush off any dirt or wash and then dry them.
2. Spray the caps with a bit of olive oil, or put some oil in your hand and rub it on. Rub the oil onto the top and bottom of each mushroom, then sprinkle them with a bit of salt on top and bottom.
3. Put them in an oven at about 350 degrees F, or a BBQ on medium, for 30 to 45 minutes. The larger the mushroom, the longer they will take. Wait until they're nice and soft, and wrinkling around the edge. If you keep them bottom up, all of the delicious mushroom juice will pool in the cap.
4. Serve these with your favorite toppings, and eat them on their own, baked as a pizza, or put on a bun as a burger.
Source of recipe: To watch a free video of me making this portobello mushroom burger recipe, so I can show you the exact techniques that will make the perfect recipe, go to http://www.healthyveganrecipes.net/video/portobello-mushroom-burger-recipe [1]