Cut potatoes into smaller pieces and cook for ~10 minutes or until soft – fork goes through easily.
Strain potatoes and push them through potato press (like the IKEA one) back to the same pot. Add a pinch of salt.
Add a splash of milk and a cube of butter. Mix until combined and butter melts and incorporates. Repeat this step until desired consistency is reached.
You can press the mashed potatoes through a sieve for maximal smooth consistency.
Don't blend potatoes – pressing them preserves better texture.