I've done something similar with big tomatoes, laying the slices out on a pad of paper towels for a while first. (smittenkitchen.com)
For bigger tomatoes, roast at a higher temp for about 2 - 3 hours. (smittenkitchen.com)
This didn't give the bread the nice orange color that very finely chopped tomatoes do, but bigger tomato pieces mean more flavor when they're bitten into! (tofufortwo.net)