Can someone give me a quick rundown on how to do Arena?

So at first I was going to ignore the arena quests, but then I saw that one of the quest rewards was for cheese, and I simply cannot ever get enough cheese. The requirements for the cheese is to complete both the rathian and chatacabra arena quests in 10 minutes or less, which seemed doable enough. However after a couple of attempts with Rathian I find myself kind of struggling, with my current best time being 13 and a half minutes. For some reason I'm not allowed to bring or cook a meal in the arena, resulting in me having a much lower max health total than I'm used to. This leads to me needing to play more cautiously, which in turn makes the fight a lot slower. I'm sure a lot of this is simply skill issue, but I'm wondering if I'm missing some key mechanic due to just not being familiar with how this game works. Any advice for getting Rathian down in sub 10 minutes? Please understand I need that cheese (also why are cooking ingredients so hard to get in this game?).