When you first enter the kitchen (after the hunger sequences and the rat :P ) you have to go by one of the chefs in the first room. The risky way is to start the chase and have the chef stuck (looking under a table) as you climb the cabinet on the far-right corner. BUT ... there is a way to do go through the kitchen just as fast, and without the risky chase. Here's how you do it:

• as you approach the kitchen, you slide through the first hole, so you don't get noticed by the chef right way;
• as you emerge on the other side, start jumping right away, and keep doing instant jumps on each landing (so the chef doesn't hear you run)

NOTE: it's important to have enough stamina, so be careful about stamina management just before the kitchen, avoid unnecessary jumps or long sprints up until this point.