Make the meatballs. Preheat oven to 400F and line a sheet pan with foil or parchment paper.. In a large bowl, mix turkey, panko, eggs, cilantro stems, half of fresh ginger, half of fresh garlic, sesame oil, fish sauce, soy sauce, salt and pepper. Roll into golf-ball size spheres and place on prepared sheet pan. Bake until golden brown, 20-25 minutes, rotating the pan half way through.
Roast the broccoli. Line another sheet pan with foil or parchment paper. Mix florets with 2 tablespoons olive oil, salt and pepper. Roast until barely golden brown, 15-20 minutes.
Make the curry. Heat remaining 2 tablespoon oil in a large skillet over medium heat. Saute scallions, remaining half of fresh ginger, remaining half of fresh garlic, and red pepper until pepper slightly softened and garlic and ginger are fragrant, 2 minutes. Add coconut milk, red curry paste, and curry powder, and sugar, whisking until smooth. Let simmer for 5 minutes. Season to taste with salt, pepper, and lime juice (you can also add more sesame oil, fish sauce, and soy sauce here, if desired). Add meatballs and broccoli, tossing to coat in curry sauce. Serve over white rice with limes and cilantro immediately.