The first thing to do is to put water in a large pan. When the water start boiling, put the tomatoes intyo it and switch off the fire. Cover the pan and let the tomatoes inside for 15 minutes. In this way they will get tender. while waiting, cut the garlic in slices, not too thin because you will not eat then and it will be easy to avoid them when you will serve the tomatoes. Rinse the capers to loose all the salt and dry them.
When the tomatoes will be reasy strain them and put them to dry on a cotton cloth. In a large jar start putting a layer of tomatoes with some garlic, capers, origan, chili and extra virgin olive oil and continue untill all the tomatoes are well dressed. After one hour you can start putting them in the cans. Pay attention to cover them with the olive oil. Now you have to pastorize the cans. It's simple. You put them rolled in cloth so they don't break in a pan. Put water untill the cans are covered for 3/4 and let the water boiling for 40 minutes.
You can use them when they are perfectly cold. They are very good in Winter with boiled meat, but you can serve them with a good glass of wine for aperitif. An interesting variation is to put them into the mixer avoiding the garlic and put the creme on small toasts. Or you can make a sandwich with two tomatoes and some cheese like Brie inside.
The last thing: don't you worry about all the olive oil that you will use, because you are not going to loose it. When a can is finished, and believe this happen very quickly, you can filter the oil and use it for a pasta.