Dear PompeYams:
Your selection of olive oils sounds wonderful and I imagine that your culinary creations using these oils are delicious.
At the moment, some of my favorite olive oils come from the following regions:
1. Tras-os-Montes, northeastern Portugal.
2. Mani, southeastern Peloponnese, Greece.
3. Kolymbari, northeastern Crete, Greece.
4. The highlands of Sardinia, Italy.
5. The hillsides of Alpes Maritime, France.
6. Umbria, Italy.
7. Tuscany, Italy.
8. Jaen, Anadalucia, Spain.
I would like to point out, however, that the Olive Tree World is a world of constant discovery. I just received a small sample from a family olive grove situated in the Sicilian highlands that was excellent. I am continually learning about new regions that are not really publicized and that yield a cornucopia of flavors for the appreciative palate.
As I have endeavored to explain in my web site, I have come to understand that there is a very direct interrelationship among certain olive oil producing factors that will influence the organoleptic characteristics of the resulting oil. Putting this simply, the more care that is given to the olive variety selection/growing/harvesting/production/storage process,the better the olive oil will be.
During the course of my research of olive oils, I try to find out what olive varieties are used, what farming techniques are used for the cultivation of the trees, whether it is a blend oil or a single estate, how the olive oil was produced, how the olives were harvested, how long it takes from harvesting to pressing, what method is used for pressing, how the olive oil is stored before it is bottled, the duration and location of storage (because temperatures and light exposure are very important here) before they reach your kitchen. Basic rule of thumb: If the price of the olive oil is disproportionately lower than the current market prices, one should be wary.
If you are looking for organic olive oil, always ask for a copy of the organic cerificate and make sure that it is issued by a reputable certifying authority. Currently, the U.S.D.A. is in the process of initiating its American certification of international organic food products certifiers. The department began accepting applications for certification on April 1, 2001 and will release its first list of U.S. certification of foreign organic food product certifiers in 2002. This will provide you with another resource for organic verification.
I hope that this helps. I am a great proponent of the culinary philosophy that it is always important to consider the right olive oil for the dish you are preparing. Some olive oils (like the ones from Jaen) have a very strong taste that go beautifully with certain dishes but can overpower others.
Ask your supplier questions about the olive oil that he is supplying to you. If he cannot answer your questions, find one who can. There are a lot of good professionals in our industry and you should be able to locate one in the UK. Another hint: A good table olive producer does not necessarily produce the best olive oil. The converse is also true.
I hope this is of assistance.
Have fun in your olive oil explorations. It is evident that you are enjoying your discovery of a wonderful world with a rich culture that takes great pride in its contribution to the culinary arts.
Olive Oil for Papa Chef 
