Chicken GOPM with what was on hand

I had half a boneless skinless chicken breast, and yesterday afternoon I decided to marinate it, so I poured a lot of ponzu sauce over it in a covered storage dish (the glass kind with clamp-on lid) and shook it from time to time during the evening and today. Then I rubbed the inside of the 2.25-qt Staub round cocotte and lid with toasted sesame oil and put in layers of food I had on hand:

1/2 c pearled barley
2 Tbsp brown rice vinegar
thickly sliced frozen leeks from Trader Joe’s (not thawed)
several cloves garlic, minced
2 stalks celery, chopped
the marinated chicken breast, but into chunks
1 good-sized carrot, diced
1/2 small head of Savoy cabbage, cored and chopped
2 Roma tomatoes diced

Pour-over:

1.5 Tbsp toasted sesame oil
1 Tbsp brown rice vinegar
2 Tbsp ponzu sauce
2 Tbsp sherry
1 tsp Colman’s mustard (the dry powder)

Shake well, pour over, cover, and put in 450ºF oven for 45 minutes. Very tasty.