The subject comes between in sentences like these, both for objects, particles, and prepositions. The subject needs to be there, right after the verb, and even particles (like om in tycka om) are separated from the verb.
No, that would be essentially "How do you fix/prepare?" "Laga" can be applied to many sorts of things. It also means "repair", for example. "Laga mat" means to prepare food, "laga bilen" would mean to repair your car.