We used the aforementioned focaccia bread (a day old and left out to stale a bit overnight), and threw in some homemade mozzarella, but you can improvise as you wish. Here's the recipe we used:
Serves 8 (or 4 if you're really, really, really hungry)
6-8 cups of day old bread, cubed (not the sliced bread from the grocery store, but good, rustic bread)
6 Ripe, juicy tomatoes, diced into 1" pieces, seeds removed
1/2 cup fresh Basil leaves, sliced into a very thin chiffonade
1/2-3/4 cup Olive Oil, plus a little extra to toss with the bread (maybe another 2-3 T.)
1/4 cup Red Wine Vinegar
1 tablespoon Dijon Mustard
1-2 Garlic Cloves, minced
1/2 pound Fresh Mozzarella, cubed (totally optional, but delicious)
Preheat your oven to 400-degrees. Scatter your bread cubes onto a baking sheet with sides and toss with 2-3 T. of olive oil. Bake fore 10 minutes, or until a little crunchy but not tooth-breakingly hard. Cool.
Pour red wine vinegar into a large bowl. Add Dijon Mustard and whisk until combined. Slowly drizzle in 1/2 to 3/4 cup olive oil, while whisking. (Hint: The less oil, the more tart the dressing, and I like my dressing tart.)
Add garlic to the dressing and whisk to combine.
Add diced tomatoes, bread, fresh basil and if using, the cubed mozzarella to the dressing. Sprinkle with a good bit of salt (1/2-1 t.) and pepper (1/4-1/2 t.). Toss to coat. Serve immediately.
Ta-dah! Summer in a bowl I tell you. Not the sexiest picture you'll see, but it is yummy! Make it, love it, enjoy it. Happy summer!