Today's clue ladder, gentlest first. In the game each rung is worth fewer points, so open only what you need โ the answer stays hidden until you ask for it.
In 1995 I became the first of my kind ever grown beyond the sky, sealed aboard a shuttle.
I grow hidden underground, plain and starchy, and I have toppled empires and crossed oceans.
When a blight rotted me in the ground, a million people in Ireland starved.
Boiled, mashed, or roasted, I come in a thousand varieties and anchor dinner worldwide.
Peeled, sliced thin, and dropped in hot oil, I become the world's favorite golden fries.
6 letters, starts with โPโ.