To make Mushroom Balls: Soak the almond in water for 30 minutes. Drain. Preheat oven to 375 degrees Fahrenheit. Put almond, portabella, celery, onion, oregano and lemon juice in a blender, pulse a few times. As long as the ingredients are mixed, it’s okay. Don’t blend too long and make into a puree. (Note: You can stop here and use this mushroom dough as a spread and serve on bread. In that case, you can use the tomato sauce as another layer of spread and make a 3-layer sandwich.) To make mushroom balls, continue. Take one spoonful of mushroom dough at a time, shape into balls. Place the mushroom balls on a baking dish, bake for 10 minutes or until a little dry on the outside. Use a big flat spoon to transfer the mushroom balls to a plate, as they might be fragile. To make Tomato Sauce: Mix tomato, red bell pepper, garlic, basil, salt in a blender. Add water if you want it thinner, and more salt to taste. Serve mushroom balls on lettuce (optional) and top with tomato sauce or on the side.