This is the 10170th most frequent Polish word.
botwinką
"Botwinką" refers to young beet leaves, stems, and roots, often used in Polish cuisine for soups or salads.
Here, 'botwinką' is in instrumental case as part of the expression indicating the ingredient used for cooking.
Na obiad ugotowałam zupę z botwinką.
For lunch, I cooked soup with beet greens.
In this sentence, 'botwinką' also appears in instrumental case, describing what fills the dumplings.
Moja babcia zawsze robiła pierogi z botwinką.
My grandmother always made dumplings with beet greens.
The term 'botwinka' identifies the specific part of the plant being referred to in the sentence, used in nominative case as the subject.