Combine flour, yeast, salt, and sugar in a bowl.
Add warm water and butter, and mix to a soft, slightly sticky dough.
Knead for 8–10 minutes until smooth and elastic.
Cover and rest in a warm place for 1 hour, until doubled.
Divide into 8 equal pieces. Roll each into a round roughly 5mm thick.
Heat a dry cast iron pan or skillet over medium heat — no oil.
Cook each flatbread for 3–4 minutes per side until lightly golden with dark spots.
Keep warm wrapped in a clean cloth, or cool on a rack.
Serve with: lingonberry jam, butter, smoked fish, or alongside a hearty stew. In the Sámi tradition, gáhkku accompanies nearly everything.
