Based on several examples on the internet- I made myself a casserole carrier. Pretty easy peasy. I cut a 22 by 22 inch square of two fabrics. Along with a 22 by 22 piece of Insul Bright. Clipped equal triangles of the corners. Turned in edges and top stitched. Made a strap and sewed it on. Then made the little loops that went over the handle. Done!
135