I'm going to disagree here for two reasons.
1) Everyone is jumping on the Se bandwagon. I see it differently.
Yes, Se is about noticing details - scanning the current situation about what is important and relevant. But, more importantly, it's about taking in information with an eye to focusing what actions to take to move forward - looking for relatable patterns and focusing on what the possibilities are for what do to next.
I think Ramsay is much more of a Si user:
He is scanning the current situation for what is DIFFERENT from what it SHOULD be. He is noticing discrepancies based on his past experience for what it SHOULD look like, smell like, taste like. He's using what he has already experienced and weighing what is in front of him against that. He's focused on what has worked in the past.
I think he is a Si user.
2) The general consensus here is that he is an ENTJ. Where I disagree:
I can't speak for all ENTJs, but based on my personal experience, when I create something, it's completely new. Everything goes out the window and I start from scratch trying to find the best possible way to do something. It doesn't matter how it was done before. It's a big picture view with a newly defined goal in mind. I think outside the box. Well, more accurately, I'm not even aware there IS a box.
Yes, Ramsay is about efficiency (Te), but Ramsay is an inside the box kind of guy. He goes into an existing restaurant and tweaks things to make them run better, or opens up a new restaurant, or gives guidance to new chefs. Yes, it's efficient, but it's the same thing over and over. He's taking what he knows will work based on his past experiences and applying it to a similar situation. Everything he does is relatable to a past experience rather than a new idea.
I vote ESTJ