If the food cooks faster and/or browns faster in one place in the pan than in another, then there is a problem with either the heat, or with the pan. This is more likely to happen with pans that have thinner bottoms, than with those with very thick or multi-ply bottoms. The pans I use most in my own kitchen have the three-ply bottoms, constructed of a thick slab of aluminum encapsulated in stainless steel. Not only do they heat more evenly, but they also require less heat to achieve good results. Thinner pans tend to heat up fast, but also lose heat just as quickly. And the heat that is delivered to the out edges is simply absorbed into the air.
In my own experience, if the food is burning in one side of the pan, while food in the other side is barely cooked, it has more often been the heat. Read on:
My daughter has a gas range. It only works okay if neither the AC nor the heat is on. One vent is located in the kitchen ceiling where the air blows onto the cooktop. The flame is pushed away from the front of the burners, so that any pot on the stove receives more heat on the back side, than on the front. It is not pleasant to cook under this condition, as the food is continually needing to be rearranged for even cooking.
My stove, on the other hand, is electric. It also is prone to problems. One of the burners heats very unevenly. Since the burner glows red on high heat, it is easy to see that some portions of the burner are getting much hotter than others. Even with heavy pans, this presents problems, but I cope.
Checking for Even Heating 
