@mbassani91,
You are hearing but not listening. There's not very many people that ask for cookware for their birthday present. As such, she's thinking about the best product with the most value to further engage in an activity she really enjoys. So, she seeks out opinions on the subject, up to and including a person that cooks as a vocation.
In turn, you've taken this as a personal slight, as that "somebody" just happens to be a blast from the past with romantic ties. That relationship has run its course and has been over for many years. She's not interested in a romantic relationship but she is very interested in how he's excelled in his profession.
Your jealousy and pouting caused her to break those ties. She is very concerned that you cannot control your feelings and wants to alleviate any more undue stress from the situation.
Here's the thing you're not seeing. You've just caused a rift you may not be able to understand or control. She told you she really wants to cook professionally. Instead of cultivating that thought, you double down on the thought she may still have romantic thoughts about him and wants to dump you.
This isn't about you. It's about her, her hopes and dreams and...well, that's probably not feasible for her to do now since you've made it all about you.
So, the question is now, would you like to support her aspirations or do you still want to make everything about you?