Japanese Beef Bowl (Gyū-don)

Ingredients

• 7 ounces beef very thinly sliced, note 1
• 1/2 onion large, about 130g, cut into 1cm wide wedges
• 1 1/4 cups dashi stock
• 2 tablespoons sake
• 2 tablespoons mirin
• 1 tablespoon sugar
• 3 tablespoons soy sauce
• 2 cooked rice in a large serving bowl, about 200g per bowl
• shallots Finely chopped, scallions
• pickled red ginger note 2