If you are thinking that I am going to preach meditation and yoga to find out your passion, then drop all your assumptions, because then you are still not ready to do meditation with an assuming mind!
But how can the mind not assume anything? It is in its nature to form an impression about whatever it gets its attention on! And how can the mind not put its attention on everything it comes across? The real answer lies in the fact that it not about what the mind wants, it is about what this life wants. The key is to focus on that vision and not get tricked by the pitfalls of the mind.
One classic pitfall is the viewpoint of giving all importance to the ends rather than the means to achieve those ends. People tend to think of accumulating some wealth before living it up passionately. It is not that making money cannot be a passion, it is just that there can also be alternative ways to survive in the cold-blooded world out there. If you are really passionate about something, then there is no doubt that you will create something worthwhile as well as valuable for this world to acknowledge, appreciate and pay!
One simple way to figure out your passion is to observe the First thing that you do after finishing your work/studies for the day. The answer to your question might be hidden in that particular habit of yours. For instance, a 'rather healthy' friend of mine had this habit of watching cricket in his free time. Everyone used to tell him that why do you still watch cricket when you are already 30 years of age and ineligible to play professional cricket. He didn't care about their opinions and continued with his habit. Now he is seriously considering to try his hands on cricket commentary and/or sports analysis.
Thus, becoming conscious of these small things in life can make a big difference when it comes to shaping up a life of fulfillment and satisfaction.
P.S.: "You just take care of the Immediate (good habits), I will take care of the Ultimate (end results)!" - Sg