Wash the fresh lotus root under cold running water, peel, and slice into thin pieces. Soak slices in water mixed with lemon juice or vinegar.

In a saucepan, bring water combined with lemon or vinegar to a boil. Blanch lotus root slices for about 2 minutes, then drain and rinse under cold water.

In a bowl, whisk together soy sauce or tamari, sesame oil, sugar, and cornstarch. Add a splash of water to mix thoroughly.

Heat light oil in a skillet over medium-high heat. Add minced ginger and garlic, stirring for about 30 seconds until aromatic. Toss in blanched lotus root slices with Sriracha.

Pour the sauce over the lotus root and cook for another 2-3 minutes until thickened. Stir occasionally to prevent burning.

Remove from heat, transfer to a serving platter, and garnish with sliced green onions and red pepper flakes if desired. Serve immediately.