Heat a big skillet or sac tava, add olive oil and ground beef. Stir frequently to cook on medium-high heat until it changes its color.
Meanwhile diced onion, green and red peppers, and peeled tomato. When the ground meat is cooked make a well in the center and add the onion. Cook for about 2-3 minutes and stir everything. You can halfway close the lid from time to time while cooking.
Next add the peppers, again making well in the center, cooking the first 2 minutes and mixing everything. Repeat the same steps after adding the tomato.
If your meat doesn't have much fat, add 1-2 tbsp butter. Season it with salt, peppers, and cumin.
Add about 1/4 cups water, close the lid, and cook for about 5 more minutes until everything is soft. Your home-style tantuni is ready.
If you don't want to make a lavash wrapping bread just buy any flat wrapping bread and continue to assemble after slicing the fresh veggies.
Cut the red onion in half and thinly slice. Rub it with sumac and salt, transfer it to a small plate. Thinly slice other veggies and pickles and place it to another wide serving plate. Fold the lavash bread in half and arrange it into another serving plate.
Reheat the tantuni and bring everything onto the table. Pour some of everything generously :) Wrap it and enjoy it! Afiyet olsun!