Cut the sweet potato and the old bread into small cubes. Peel and halve the onion, then cut into fine strips. Quarter the cherry tomatoes and remove the stalk. Put everything together in a bowl and add the chives. Now drizzle everything with olive oil, pour over the Italian herbs and mix everything well. Season with salt and pepper to taste.
Put the mixture in a grill bowl and let it sizzle on the hot grill for about 45 minutes,
Stir every now and then.
I use a kettle grill. But I think if you cover the grill tray, it works on any grill.