porcio

No -ci- in there. Esperanto has no -ci- suffix, so porc- + -i- + -o is not a reading, and there is no root porc- either. Porcio is one root, and the -cio ending it wears is simply how Latin -tio nouns come into the language: nacio, stacio, funkcio, porcio. Learn the shape as a shape and it stops looking like morphology.

Porcio against parto. They are cousins in Latin and different words in use. Parto is a part of a whole in the abstract - a part of a book, a part of the country. Porcio is a share measured out and handed over: a plate of food, a ration, an allotted amount. If somebody serves it to you, it is a porcio; if you can point at it inside something bigger, it is a parto. Peco, a piece, is the third of the set and means a lump broken off.

Watch the da. With a quantity noun the material takes da, not de: porcio da supo, a helping of soup. Porcio de la mono would mean a portion of that specific money, which is a different sentence. The quantity article has the da and de split in full, and it is one of the two or three things learners get wrong for longest.