In medium frying pan, cook onion until softened.
On medium heat, add roasted garlic cloves, portobello stems and kale. Once kale turns vibrant green and it is softened. Turn off heat.
In,the frying pan, to the onion-kale mixture, add mayonnaise, onion salt, Asian Pickled Mustard Cabbage (or substitute) and gently combine.
Smoke 4 portobello mushrooms 10 minutes at 300F on Gateway Drum Smokers or 350F on other type of smoker or 375F in oven, top side down.
Flip mushrooms and smoke or bake for additional 10 minutes. Portobellos should start to soften.
In the mushroom well, spoon onion-kale mixture into portobello.
Smoke or bake for additional 5 minutes until mushroom is softened.