Thai waterfall beef salad (Nam tok)

Steak marinade
1.5 pounds steak (I used flank)
3 Tbsp soy sauce
1 Tbsp dark soy sauce
1 Tbsp sweetener
1 Tbsp lime juice
1/8 tsp black pepper
1/8 tsp white pepper
1 tsp grated garlic
2 Tbsp vegetable oil
Mix all the ingredients and let the meat sit minimum 30 minutes. Cook however you like, I sliced into chunks and cooked on my cast iron until medium. Rest and slice into bite size pieces. Do not discard juices, as they mix with the dressing.
Dressing
1.5 Tbsp fish sauce
2 Tbsp lime juice
Chili flakes, to taste
3 Tbsp thinly sliced shallots (I only had yellow onion)
1/2 cup loosely packed mint leaves, chopped roughly
2 Tbsp of finely minced lemongrass
2 Tbsp roughly chopped cilantro
2 Tbsp thinly sliced green onion
Combine all the ingredients for the dressing, and pour over steak.