I made a batch of meatballs in tomato sauce this morning. I use my biggest pot, a 13 qt Le Creuset casserole. I use a commercial #10 can of ground tomatoes. Every time I use it, no matter how careful I am, the center of the pot above where the gas burners come in contact with the bottom of the pot scorches and deposits a black burnt tomato residue. I have to move the pan around & simmer less so I won't impart a nasty flavor in the sauce. The pot is old and the interior very slightly discolored from use. Anyone else have this problem and do you have a solution?