⅓cupfinely shredded Parmigiano-Reggiano cheese (I used a Microplane)
2Tbspchopped fresh herbs (I used rosemary, sage, oregano, and chives)
⅛tsptable salt
⅛tspfreshly ground black pepper, plus more for garnish
116 ozloaf very thin white bread
5-6(6-oz.) heirloom tomatoes, varying in color
Garnish: fresh oregano sprigs
Instructions
Combine mayonnaise and next 4 ingredients in a small bowl. Set aside.
Using a 2-inch round cutter, cut bread slices into circles, reserving trimmings for another use, if desired. Slice tomatoes into 1⁄3-inch-thick slices. (If tomato slices are larger than 2 inches, use the same 2-inch cutter to cut tomatoes into circles.) Generously spread mayonnaise mixture on 1 side of bread rounds. Top each with a tomato circle.
Notes
I tested with Pepperidge Farm Very Thin White Bread.