While certain, less-well known products may be difficult to find, the Netherlands does have international grocery stores in most cities, where you can find a variety of products from all over the world. Mainstream Dutch supermarkets like Albert Heijn, Boni, Hoojvliet, Jumbo or Coop often have "international" sections with foods from various cultures, while "Tokos" usually sell exclusively international products. 

Additionally, nearly every city has Turkish or Arab supermarkets, street markets and butchers like Özbaktat in Apeldoorn.

It is also easy to find products from any culture online by Googling keywords like "[Culture/Country]+winkel" ("winkel" means "store" in Dutch). If you cannot find what you need in a physical store, there are tons of online shops which can provide what you need!