Vegan "Bulgogi" Korean BBQ Beef (gluten-free, refined sugar free, oil free option)

Name: Vegan "Bulgogi" Korean BBQ Beef (gluten-free, refined sugar free, oil free option)
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: Korean, Asian
Ingredients: 1-2 cups soy curls (rehydrated*); 2 cups shiitake mushrooms (roughly chopped or pulsed in food processor until chunky); 1/2 small onion (thinly sliced); korean barbeque marinade; 1/2 cup gluten-free soy sauce; 1/4 cup coconut sugar; 1 tbsp rice vinegar; 1/2 tsp sesame oil; 1/2 tsp black pepper; 2 tsp fresh ginger (grated); 4 cloves of garlic (minced); 1 tbsp red pepper flakes; 3 scallions (thinly sliced); optional; 1 tbsp arrowroot powder (or sub cornstarch); water; garnish; scallions; additional sesame seeds