its great to see enthusiasm from someone young, but i think ur still needlessly fetischizing good food. why do u need to make a time limit for it? its not a test. if ur really interested in learning to cook, shouldnt u be spending more than 15 or 30 min on the dish? in the beginning, just doin prep work can be very slow until u become comfortable with basics. simply cutting meat and excising fat, or chopping veges can take a good chunk of time. it still does for me anyway. this quick meal thing may be appropriate for working parents, but i dont think its for a beginner.
i'll get off my soap box now

the beef and brocolli was an interesting variation on the chinese dish in terms of flavor. completely nontraditional besides the ginger. the one thing i have to suggest is to 'velvet' the beef so that its soft. i could tell from how long the beef was in the pan that it was going to be relatively tough. ur guests will expect tender beef from previous experiences w/ the dish. if the dish is too watery, add a spoon or 2 of corn starch to thicken it. the sauce needs to stick to the meat and vege, not just be lying on the bottom of the pan.