While beef is browning, dice your bell pepper, shred cabbage and chop green onion.
When beef is done cooking, remove from pan and place in a large bowl.
Drain the fat from the pan and throw away. Then add sesame seed oil and all the vegetables except cilantro to the pan. Cook until desired softness. I cooked mine for about 8 minutes.
Remove from pan and add to beef. Leave the liquid in the pan.
Add in chopped cilantro, vinegar, fish sauce and coconut aminos. Mix well.
Place meat and veggie mixture onto butter lettuce leaves. Enjoy!