Chances are you have been dabbling in some Gourmet cooking anyway at this point and you're already way past level 5. It will take some time to reach level 8 in the career, so give yourself the best chance at progress bar improvement by continually addressing mood, daily requirements, work tone, etc. Cooking 3 Gourmet meals at a single event should not be too much of an issue though don't dilly dally and socialize too much - I would focus on making fast Gourmet meals like Caprese Salad which avoids the stovetop and oven altogether. Remember, you only have 6 hours.
Fresh Chef Reward Trait
All I can say about the Fresh Chef reward trait is...wow. I mean seriously. A cooking Sim with this trait will never have food spoil and the meals turn out amazing which means great moodlets for everyone eating the food. It's hands down one of the best reward traits for completing an Aspiration in the game.