Put whole wheat flour, perilla seed powder, and cocoa powder in a bowl and mix well.
Add yeast, salt, olive oil, and warm water, then knead into a dough.
Cover with plastic wrap and let rise for 1 hour in a warm place (first proofing).
Punch down the dough to release air and shape it into a round loaf.
Place on a baking pan and let rise for an additional 20 minutes (second proofing).
Bake in an oven preheated to 180°C for 25 minutes.