Preheat oven to 450 degrees. Line a rimmed baking sheet with foil and spray with non-stick cooking spray.
In a medium bowl, combine all of the ingredients for 1 lb. ground beef. 1/4 cup Greek yogurt. 2 green onions. 1/2 teaspoon chili powder. 1/2 teaspoon curry powder. 1/2 cup breadcrumbs. 1/4 teaspoon salt. 1/4 teaspoon pepper and mix well using your hands. Shape into walnut sized balls and place on the prepared baking sheet.
Bake for ab out 15 minutes, or until cooked through and brown on the outside.
Meanwhile, make the sauce. In a large skillet over medium-heat, heat 1-2 tablespoons olive oil. Add the 1/2 cup diced onion and cook until soft, about 5 minutes. Add 3-4 cloves garlic and 1 tablespoon grated fresh ginger and cook 2-3 minutes more.
Stir in 1 tablespoon red curry paste, 1/2 teaspoon curry powder and 1/2 teaspoon chili powder. Whisk in 1 14 oz. can coconut milk and bring to a simmer. Stir in 1/2 cup heavy cream and simmer until the sauce thickens slightly, 5-10 minutes.
Remove the meatballs from the oven and add them to the sauce, stirring gently to coat. Cook 5 minutes.
Serve meatballs and sauce over cooked rice. Garnish with fresh chopped cilantro before serving.