Heat your cast iron skillet over medium heat. Add the ghee, onion, celery, carrot, brussles, salt + pepper. Saute until the vegetables have softened, about 5-7 minutes, stirring occasionally.
Add in the ground meat, break it up and stir it in with the veggies. Cook for 2-3 minutes until almost cooked through.
Add in the bag of frozen cauliflower rice (just add it in frozen). Cook until the cauliflower rice is thawed and any moisture has evaporated, about 7 minutes.
Add in the garlic and cook until fragrant, about 30 seconds. Then add in the curry powder, dried ginger and fish sauce. Cook for 1-2 minutes. Taste for salt, pepper, seasoning and adjust if needed. Remove from the heat and allow to cool for 5 minutes. (I don't like super hot filling in my lettuce wraps).
Make the lime aioli by combining the mayo, lime zest, lime juice and salt.
Serve the curry pork mixture in lettuce wraps topped with lime aioli, chopped cashews and cilantro