The Texas heat is going to bear down on us soon, and cool suppers will be at the top of my list when I walk into the kitchen. This beautiful array of jewel-toned ingredients whips up to fill a tortilla quickly and doesn’t require heating up the oven. After stirring up the mixture, I slice some cool, creamy avocados, and I lightly toast corn tortillas on the stovetop. Flour tortillas may also be us…