In a food processor or blender, mix together the mustard, green onions, vinegars, soy sauce, and brown sugar. Slowly add the oil and mix until well blended. I only used about half of this to marinate the chicken so will need to do something else with the rest. I marinated the chicken tenders for about an hour, but if I'd actually made a decision about what to cook sooner, I would have happily done it all day and think it would have been improved.
Sauteed Potatoes
Peel and dice the potatoes and cook in the butter and oil. Basically, make sauteed potatoes. Remove to a dish when crispy and keep warm.
Sauteed Chicken Tenders
Add another bit of oil and add the chicken tenders. I browned the chicken in the oil and then put in a 400 degree oven to finish cooking while I cooked the cabbage.
Sauteed Cabbage
I added another tablespoon of oil and put in the sliced cabbage, stirring about 10 minutes until softened, seasoning with salt and pepper and lemon juice. If I were to do this again, I'd add some vinegar now. We came up with the need for vinegar at the table so added it then. And a bit more salt.
When the cabbage was softened, I added back the potatoes and made sure everything was heated up. The chicken was done by then. I put the cabbage and potatoes in the serving dish, sliced up the chicken, and put it on top.