Sauce: Place water and cornflour in a bowl, mix. Then add remaining ingredients and mix. Beef: Place in a bowl and add 1 1/2 tbsp Sauce. Mix. Broccoli & Noodles: Bring a large pot of water to the boil. Add broccoli, cook for 1 minute. Add noodles then after 15 seconds, use a wooden spoon to separate the noodles then immediately drain (don't have the noodles in the water for more than 1 minute). Heat oil in a large skillet over high heat. Add garlic, quickly stir. Add onion and cook for 1 minute until it's tinged with brown. Add beef and cook until it changes from red to brown. Add noodles, broccoli and sauce. Toss together for 1 1/2 - 2 minutes or until Sauce thickens and coats the noodles. Sprinkle with sesame seeds and shallots, if using, and serve!