Add the pineapple puree, coconut aminos, and Worcestershire sauce.
Bring the sauce up to a boil. As soon the sauce boils, turn it down to a simmer. Let the sauce bubble slowly for about 20 minutes. It will cook down a little and thicken.
In the meantime, heat coconut oil over medium-high heat in a large skillet or electric skillet.
Working in batches, sear and brown about ⅓ of the meat on one side for about 2 minutes. Flip and quickly cook about 30 seconds, the meat is thin, so it won't take long. It's also lean so don't overcook it. Set first batch aside and continue until all meat is seared.
Place all the seared meat back into the pan. Add the pineapple and coconut aminos sauce. Stir to combine and heat everything through.
Place meat on a serving platter and sprinkle generously with the sesame seeds and then the green onions.
Recipe by Laughter and Lemonade at https://www.laughterandlemonade.com/sesame-beef/