I wouldn't bother with the bread part, but you can do a tomato & basil 'salsa' beforehand and keep it in the fridge, and slice the mozzarella. Just bung it on the bread when needed and toasting it doesn't take any time. Could go some right now actually...
not really - but they're so quick, you shouldn't need to.
get good bruschetta bread and if you can't find any, then look for pain rustique or similar
get good (tasty) fresh tomatoes - roughly chop, put in a sieve, add salt to taste - leaave over a bowl for 10 mins or so - this will get rid of excess water. also, if there's loads of seeds, try and take some out as you really only want the flesh mozzarella di bufala - roughly chopped or sliced clove of garlic olive oil
rub one side of each bread slice with the garlic clove drizzle each slice, garlicy side up cook the bread in a hot pan - preferably a griddle pan or a bbq is good to cook both sides when bread is toasted put on a tray add tomatoes and mozzarella put under the grill
when cheese starts to melt, they're done.
add a few sprigs of fresh basil to serve if you have it.