Meatballs and sauce, in bread

Around here the end-of-year readings by graduating MFA students serve as events for both celebration and farewell, and at the last one KS and WP took the opportunity to host a potluck at their house beforehand, providing a full pasta bar for everyone as part of the festivities. On the toppings menu were meatballs, mushrooms, asparagus, broccoli, and shaved Parmesan; marinara sauce, pesto sauce, alfredo sauce, and browned butter. They also cooked up a giant bowl of ziti, which sat steaming in the middle of all these ingredients, asking politely for adornment.

I used the occasion to take care of the remainder of a bag of frozen meatballs that had been languishing in the freezer (several months earlier I had bought a large bag, thinking they would be convenient, but since then I'd resolved to start making my own instead). I had stuffed bread in mind, since the last version had been so successful. Plus, it was the kind of dish that I could use to finish up other items in my fridge and pantry, which is exactly what I was going for.

Call it a bread of odds and ends. Into the filling went the meatballs (halved), an onion, a head of garlic, a can of diced tomatoes, half a can of tomato paste, and half a jar of pineapple salsa. I also included what remained of a bag of grated monterey jack, reserving half a cup to sprinkle over the tops of the loaves before they went into the oven.

In the end, I would've done it differently: there wasn't enough cheese, and I didn't give the bread enough time to rise after shaping the loaves, so the crust was flat. I would have cut the meatballs into smaller pieces, too. Because of their lumpy shape I wasn't able to form the bread as compactly as the last time, and once I sliced the loaves into wedges the filling spilled right out. Still, I'm not giving up on making more stuffed breads, since they're fun to make (and eat). Anyone have some healthy filling ideas?