Core and slice your cabbage into strips that are about 1cm or ½ inch wide. Add to a pot on medium heat (with onions if you are using them) stirring often.
Grind your oats in the spice grinder then add all ingredients except for the tomato paste and the cabbage to a glass and stir well.
When the cabbage (and onions) get some color on them and start to brown lower the heat to low to medium-low heat and add all the ingredients to the cabbage including the tomato paste, and stir well. Cook on low until cabbage is tender, but still has an al dente bite to it.