Toasted Pan Bagnat with Basil Vinaigrette, Heirloom Tomatoes, and Mozzarella

packed basil leaves

packed parsley leaves

large clove garlic

red wine vinegar

mustard ((stone-ground or dijon))

fine sea salt

freshly ground black pepper

good olive oil

loaf Acme's herb slab (or ciabatta) ((1 pound))

fresh mozzarella, drained, sliced a scant 1/4" thick

large yellow tomatoes, sliced a scant 1/4" thick

large red tomatoes, sliced a scant 1/4" thick

ripe avocados, halved, pitted, removed from the skin with a spoon, sliced a scant 1/4" thick

of a small red onion, thinly sliced

bunch (wild) arugula, washed and dried, woody stems removed ((about 2 cups))

olive oil

salt

pepper