We have one of those oval burners in our vacation rental. You could try a very large, good quality saute pan with an extra thick conductive base that can redistribute heat really well, like Sitram Catering/Profisserie or Paderno World Cuisine or Demeyere Atlantis. The larger 32 cm (12.6in) sizes may fit. How big is the burner? A 2.5mm copper rondeau or skillet is another (expensive) option, or a high quality clad skillet (The Demeyere Proline in a 12.6" versions). I think All-Clad makes an even bigger pan, but may not be as effective in distributing head as evenly as they are thinner than the options listed above.

There are also oval fish pans that could fit. They are available in carbon steel, nonstick, clad stainless and tin-lined copper. Some are as long as 15" on the side.

The burner measures about 10" by 5". I'd like to find an oval pan so I can still use the other burners also. I think using one really big round one will limit use of the other 4 burners. Would a fish pan work to saute in?

The fish pans do tend to be a bit shallow (less than 2 inches). If you want to "jump" the food with a single handle and want straight walls, then the field gets pretty narrow. If you don't need to jump the pan but need a little more depth, a two handled oval casserole or gratin might work.

Of course at the high end, there is the very expensive, top of the line, 2.5 mm copper oval fish pan (but less than 2in deep): Falk Pan

Old post but I cam here looking for the info so maybe this will help someone else.

https://www.zoro.com/bon-chef-cucina-oval-dish-9-14-x-5-78-x-2-14-36-oz-60029/i/G304201056/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping%20feed&utm_content=free%20google%20shopping%20clicks&campaignid=19717005315&productid=G304201056&v=&gad_source=1