After you've put the saucepan of water on to boil for the rice, heat 1 tbsp of oil in a large stockpot over medium-high heat.
Toss the beef pieces to coat them with cumin, coriander, ½ tsp of sea salt, and ¼ tsp of black pepper in a medium bowl. Add the seasoned beef to the pot, stirring or turning, until browned on all sides, ~3-5 minutes. Transfer the beef to a plate.
Add the remaining 1 tbsp of avocado oil to the stockpot. Allow it to heat. Add onion and garlic and allow to soften slightly, ~3 minutes. Add mushrooms, stirring occasionally, until they have also started to soften, ~3 minutes.
Add sweet potato, ginger, and curry powder. Stir while cooking for 1 minute.
Add beef broth and stir in the coconut milk, remaining ¾ tsp of sea salt, and ¼ tsp of black pepper. Add beef. Bring to a boil. Partially cover and reduce the heat to a simmer, allowing the sweet potatoes to soften, ~7-10 minutes.
Stir in the kale and cook until the beef and vegetables are tender, ~5-10 minutes.
Serve over brown rice. Top with fresh cilantro and a squeeze of lime juice as desired.