Mix equal amounts of mixed grain and water and let soak for 30 minutes. Add half of the strong flour, sugar, dry yeast, and soaked mixed grain to a bowl.
Add lukewarm water to the dry least, and use a wooden spatula to mix until smooth.
Once the yeast becomes bubbly add the remaining flour, unsalted butter, and salt and mix until it comes together.
Place on a flat surface and knead until the outside is smooth. Shape into a rounded ball, return to the bowl, and allow to rise (15 to 20 minutes at 40 ℃).
Once the dough has expanded to twice it's size, perform the finger test (poke your finger through to see if the hole stays open) and remove the gas. Break off into 16 rounded portions and let sit for 10 minutes.
Remove the gas again, restore their rounded shape, place in cupcake liners or molds, and let rise a second time (25 to 30 minutes at 40 ℃).
While the second rise is happening preheat your oven to 190℃ (about 20 minutes).
Once the dough has expanded to twice its original size, bake in the oven and they're done! They give off an enticing, toasted fragrance and they're absolutely delicious.
Story Behind this Recipe
I found some mixed grain bread flour in a store. I decided to give it a try and the results were delicious.
I used Tomizawa Shoten-brand mixed grain flour. It wasn't too coarse, and since it's colorful the bread looks nice as well.