Step 1
Heat a skillet over medium heat and pour in amaranth; cook and stir until toasted and fragrant 3 to 5 minutes. Remove from heat and cool.
Step 2
Dissolve yeast in 1/4 cup lukewarm water in a small bowl. Let stand until bubbly about 5 minutes.
Step 3
Mix remaining 2 1/2 cups water with toasted amaranth yeast mixture all-purpose flour bread flour and salt in a large plastic container with a lid with a wooden spoon until well combined. Cover and let rise in a warm draft-free place until doubled in volume about 2 hours.
Step 4
Dust a cutting board with 1 tablespoon all-purpose flour. Turn the dough out onto the board and briefly knead with floured hands. Shape into a ball.
Step 5
Line a large bowl with a piece of parchment paper. Place dough in the bowl and cover with a clean dish towel; let rise until nearly doubled in volume about 1 1/2 hours.
Step 6
Preheat oven to 450 degrees F (230 degrees C) after dough has been rising for 45 minutes. Place a lidded Dutch oven inside after 25 minutes.
Step 7
Remove hot Dutch oven from the oven using oven mitts. Place dough carefully inside lifting it up with the parchment paper. Cut any parchment paper that is peeking out of the Dutch oven with kitchen shears. Cover with the hot lid.
Step 8
Bake bread covered in the preheated oven for 30 minutes. Remove the lid and continue baking until top is golden brown about 10 minutes. Lift bread out of the Dutch oven with the parchment paper using oven mitts and tap the bottom; if it sounds hollow bread is done. Let cool for at least 1 hour on a wire rack.