De or het appelsla?

The correct Dutch article is:

de appelsla

Meaning (Dutch) (kookkunst) rauwkostgerecht met appel

How to use appelsla

the appelslade appelsla
this appelsladeze appelsla
that appelsladie appelsla
our appelslaonze appelsla
your appelslajouw appelsla
every appelslaelke appelsla
which appelsla?welke appelsla?
a big appelsla / the big appelslaeen grote appelsla, de grote appelsla

Dutch words ending in appelsla

aardappelsla

In compound words, the last part decides the article. See the rule

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).