Soak soy curls in boiling hot water for 10 minutes. Set these aside and heat up a large frying pan over medium-high.
Meanwhile, combine soy sauce, agave, lemon juice, garlic, ginger, corn starch, and red pepper flakes in small bowl or jar.
Once the pan is hot, fry the onions with a touch of water if needed until they have softened (around 3-4 minutes).
Drain the soy curls and add them to the frying pan. Toss well with the onions and cook for 2 to 3 more minutes.
Pour in the sauce and lower the heat to medium-low. Stir well so that everything is evenly coated the the sauce slightly thickens.
Serve over rice with sesame seeds and green onion, or with vegetables of your choice such as cabbage, broccoli, or salad.