In a large bowl combine the sesame oil, egg, 3 tbsp soy sauce and corn starch until a thin batter forms. Toss in the cauliflower and let sit while you make the sauce, tossing every few minutes to coat all pieces.
In a small bowl whisk together all the ingredients for the sauce except the broth and corn starch. Combine the broth an corn starch in a separate small bowl and whisk till no more clumps. Combine with the other sauce ingredients. Set aside.
Heat a large wok over medium high heat, add 2 tbsp of canola oil and begin to fry the cauliflower on all sides, in batches, making sure not to crowd the pan (approximately 1-2 minutes per side). Once all the cauliflower is all cooked remove any excess oil from pan and wipe clean.
Return pan to heat and add 1 tsp of oil. Add the ginger and garlic to pan and stir, cooking for 30 seconds, until very fragrant. Pour in the sauce and stir constantly until it begins to thicken. Remove from heat and gently toss in the cauliflower, turning to coat evenly. Garnish with green onions and toasted sesame seeds if desired. Serve immediately. Enjoy!