Source: Mahabharata Vana Parva 193.29

Sanskrit transcript:
अपि शाकं पचानस्य सुखं वै मघवन गृहे।
अर्जितं स्वेन वीर्येण न व्यपाश्रित्य कञ्चन॥
Transliteration:
api śākaṃ pacānasya sukhaṃ vai maghavana gṛhe।
arjitaṃ svena vīryeṇa na vyapāśritya kañcana॥
Hindi translation:
हे मघवन (इन्द्र), किसी का सहारा लेकर नहीं अपितु,
अपने मेहनत से अर्जित साग को पकाने वाले के घर में सुख होता है।
English translation:
O Maghvan, even he is happy who cooks only little leaves (for his food)
earned by his own efforts without having to depend on others.

This verse is from the Vana Parva of the Mahabharata. Sage Markandeya presents the story of Yugas (Kreta, Treta, Dapara and Kali yugas), and of Vami horses. This Parva offers contrasting views on traditional and ritualistic, as well as knowledge and personal development on vice and virtues.
Part of this chapter is this Shlok, focuses on the self-reliance of a person. The idea is to accept something lower solely earned by you than something which is better but makes you rely on someone.

Read more about minimalistic life in this post.