Drain pineapple, reserving the juice. Set pineapple aside. In a small bowl, whisk together pineapple juice, coconut aminos, ginger, honey, and arrowroot powder. Set aside.

Heat avocado oil over medium-high heat in a large skillet. Add pork and cook until browned on all sides, about 5 minutes. Remove to a plate and set aside.

In the same pan, cook onion until it begins to soften, about 2 minutes Add garlic and cook until fragrant, just 30 seconds. Pour in the pineapple juice mixture and stir to scrape up any browned bits in the skillet. Add pork and pineapple chunks.

Bring the mixture to a simmer and let cook until thickened, stirring frequently, about 5 minutes. Season to taste with salt and pepper.

Sprinkle with sliced green onions and crushed red pepper flakes. Serve over cauliflower rice, if desired.