Greek Pork Souvlaki with tzaziki and pita

you will need pork meat i used pork neck but also used allready tender loin
for six swewers marinating time 1till 12 hours
a full bowl tzaziki
2 table spoons extra virgin olive oil into pork marinate
juice of a full lemon
1 table spoon or 1 and half oregano
1 or 3 smaller spoons tyme optional
salt pepper to your taste
2 tomatos,red or white onions to your taste you can also add feta or fries for remplacing tzaziki,optional fresh parsley