Paris - What is not available locally

Every nationality has its special ingredients that make the "core" of the cooking of the country.

Traveling around the world, from east to west, from north to south, inevitably leads to places where some of this vital ingredients are missing or outrageously expensive and complicated to get to.
If you know in advance you might bring with you the missing ingredients or you might discover alternative ways of finding (or making!) a closer substitute.

Here is what  is hard to find or not available at all in Paris.

English ingredients or products:
-hot dog buns
- double cream
-english bacon
- sausage rolls
- walkers crisps (you find them but they are prohibitively expensive)
- Cadbury's chocolate (you find them but they are prohibitively expensive)
- cheddar cheese
-(good) curry

Typical Indonesian Spices and cooking ingredients:
- Kemiri (candle nut)
- Daun Salam - some people said that the English translation for it is Indian Bay Leaf (but it's different)
- Kencur (lesser galangal)
- Daun Kunyit (turmeric leaf)
- Kluwak (Kluwak nuts)
- Kecap Manis (Indonesian Sweet Soy Sauce)

Italian ingredients: aged pecorino cheese, carnaroli rice for risotto, italian wine (the good one!), fresh ricotta, fresh mascarpone cheese, italian pine kernel, dried porcini mushroom (cepes), the "true" balsamic vinegar (and not the sugary mass produced version of it).