This is like a non-recipe more than an actual recipe. But here is what I did for the sandwiches. I have made them before with homemade bread/homemade basil aioli but the simplified version is pretty much just as good.
Makes 4 sandwiches.
2 rotisserie chicken breast halves (I just bought a Costco chicken)
1-2 tomatoes
About 4-6 ounces fresh mozzarella (I like to buy fresh mozz at Costco, because it is so cheap compared to most other grocery stores, and I think it is pretty good quality)
Fresh focaccia bread, cut into 4 sandwich size squares (I bought mine from Kneaders. The pieces of focaccia they sell made 2 of the size sandwiches I made today, for reference)
Basil aioli (The link is for a more homemade sauce with fresh basil, but to simplify, all I did today was mix together some mayo and store bought pesto. Maybe 1/3 cup mayo to 3 tablespoons pesto - just until it tastes pretty good and pesto-y but not too strong)
Salt and fresh ground pepper
Balsamic vinegar
About 1 cup baby spinach leaves
Slice chicken breasts into thin slices about ¼ to ½ inch thick. Slice tomatoes into 1/4 - ½ inch thick slices. Slice mozzarella into ¼ to ½ inch thick slices. Slice focaccia down the middle width-wise so there are two slices for each piece.