Peel the outer layer of the red onions and cut a small piece off the bottom so that the onions stay upright better. Cut each onion almost all the way through four times so that you get eight wedges per onion. Be careful not to cut the onions all the way through. Place each onion on two sheets of aluminum foil.
STEP 2: Mix together the olive oil, balsamic vinegar and salt and drizzle over the onions, add the fresh herbs and fold the packets closed.
STEP 3: Place the onion packets in the preheated Weltevree Outdoor oven - indirectly on the heat in the top compartment - and bake the onions for about 30 minutes (depending on the temperature of the oven, they should be longer or shorter) until they are completely soft.
STEP 4: For the salad, arrange the avocado and buffalo mozzarella on a platter and divide the dill, lemon zest, pepper and salt on top.
STEP 5: Remove the aluminum foil and serve the onion florets with the salad. Also add the juices from the foil packets to the salad as a seasoning, if desired.