It is, though you need to use the right article.
- De lunch
- Het middageten
Can you explain what is the difference between using de and het and when is the right time to use them?
Well, to be honest, as far as I know there's no fast rule, only some guidelines. As far as I wrote down ages ago, you need to use het with:
• singular diminutives (that is, words ending in -je)
• infinitive verbs used as nouns (or other nouns formed with infinitive verbs, as middageten)
• compass directions
• nouns ending in -um, -isme, -aat (exception to the latter: except if it refers to a person, like *de soldaat*)
• nouns beginning with ge-, be- and ver- (except for those ending in -ing and for *de gewoonte*)
In all other cases, use de.
For more information, please read this article (it's 3 pages long): http://www.dutchgrammar.com/en/?n=NounsAndArticles.03