Pre heat oven to 350 degrees. Put the cherry tomatoes, onion, and fresh herbs together in a bowl, add salt and pepper along with a drizzle of olive oil, mix gently. Depending on the size of your roast you may want to make more or less of this filling.

Place the butterflied roast on a flat board and sprinkle the inside with salt, pepper, dry Italian spice blend and drizzle generously with balsamic glaze.

Put about three quarters of the tomato filling on to the inside of the butterflied roast. Then place the mozzarella on top of that. If you are using sliced mozzarella cut it into smaller cubes to scatter on top of the filling.

Roll up the roast and tie with cooking twine. Rub the outside with a little olive oil, Italian spice blend, salt and pepper. Place in a shallow baking dish.

Gently toss the quartered potatoes with the leftover tomato filling, salt, pepper and olive oil. Arrange the potatoes around the roast in a single layer.

Roast at 350 degrees until the roast is about 140 degrees and the potatoes are tender, about 40 minutes depending on size.

Serve with Marinara if desired.