Sunflair Mini Solar Oven. Its pretty good for camping and very small meals. It comes with a tray and a silicon collapsable pot. It folds up compactly so its really good for backpacking.

Downsides: its not a perfect seal. I pinch the corners with clothespins to help seal it better and that helps. Its also very small so its more of a one person meal kind of thing. The collapsable pot is nice but its very flimsy so you have to handle it carefully, especially if you have a lot of liquid in it.

Overall not a bad little thing but its not super cheap for what you get so unless you plan on taking it camping, youre probably better off getting a higher quality model or making your own.

If you want something more robust Ive heard good things about the GoSun range. More expensive (though not by much) but also better quality overall. Never used one myself though.