1/2 cup Black Japonica rice blend or long-grain brown rice (see Note)
1 cup water
1 medium zucchini, shredded using the large holes of a box grater
1 tablespoon walnut oil or extra-virgin olive oil
1 tablespoon minced fresh ginger
2 cloves garlic, minced
1 medium yellow onion, finely chopped
2 celery stalks, finely chopped
1 tablespoon curry powder
2 teaspoons Worcestershire sauce
1 teaspoon salt
2 pounds 93%-lean ground beef
1 large egg, beaten
1/3 cup mango chutney, plus more for serving, if desired