Preheat the oven to convection broil at 450F
Place the sliced cabbage and onion on a baking pan. Season with flaky salt and olive oil
Mix well and massage with your hands until slightly softened
Spread evenly and roast for about 20 minutes, mixing a few times during roasting so the vegetables brown evenly
In a large bowl, combine the chopped herbs, quinoa, dates, and nuts
Add the roasted cabbage and onions
Season with salt, black pepper, sumac, olive oil, lemon juice, garlic, Dijon mustard and date syrup
Mix everything well and serve
