Combine 1/2 cup of the rolled oats/multigrain mix (from dry ingredients) with 1/4 cup hot water and 1 tablespoon honey in a small bowl. Stir, cover, and let sit while you measure other ingredients — 15 to 20 minutes. The mixture should absorb most of the liquid and be slightly gelled; if dry, add up to 1 tablespoon more warm water.

Mix dry and wet

Combine dry ingredients

In a large mixing bowl (or the bowl of a stand mixer fitted with a dough hook), whisk together 3 cups bread flour, 1 cup whole wheat flour, 2 tablespoons dry milk powder, 2 teaspoons instant yeast, 1.75 teaspoons salt, 2 tablespoons brown sugar, and the remaining 1/2 cup rolled oats and 1/2 cup multigrain mix. Ensure yeast and salt are on opposite sides of the bowl before mixing to avoid direct contact.

Mix wet ingredients

In a separate bowl whisk together 1 1/2 cups warm water (105–115°F), 1/2 cup milk, 2 tablespoons olive oil, and 1 large beaten egg until uniform.

Combine wet into dry

With mixer on low (or using a wooden spoon), pour the wet mixture into the dry ingredients. Add the soaked oats/seeds (including any unabsorbed liquid). Mix until a shaggy dough forms, about 2–3 minutes. If dough is too sticky, add up to 2 tablespoons bread flour; if too dry, add 1 tablespoon warm water at a time until it comes together.

Kneading

Knead the dough

Knead the dough on medium speed with the dough hook for 6–8 minutes, or by hand on a lightly floured surface for 8–10 minutes, until the dough is smooth, elastic, and springs back when lightly pressed. The final dough should be tacky but not clingy.

Adjust seeds

If you prefer visible whole seeds, reserve 2 tablespoons of the multigrain seed mix and knead them in during the last 1–2 minutes so they remain intact rather than fully incorporated.

First rise

Bulk fermentation

Lightly oil a clean bowl and place dough inside, turning once to coat. Cover with plastic wrap or a damp towel and let rise in a warm draft-free spot until doubled in size, about 60–75 minutes depending on room temperature (longer in cooler kitchens).

Shape and final rise

Deflate and shape

Gently punch down the dough to release gas. Turn out onto a lightly floured surface, press into a rectangle roughly 8x10 inches, fold short sides into center, roll tightly into a loaf shape, pinching seam closed.

Place in pan

Lightly oil a 9x5-inch loaf pan. Place the shaped loaf seam-side down into the pan. If desired, brush the top with beaten egg or 1 tablespoon water and sprinkle reserved seeds and 1 tablespoon oats evenly on top.

Final proof

Cover the pan loosely with lightly greased plastic wrap or a damp towel and let the loaf rise until it reaches about 1 inch above the rim of the pan, roughly 40–55 minutes.

Bake

Preheat and score

Preheat oven to 375°F (190°C) during the final proof. Optional: make one shallow lengthwise slash across the top with a sharp knife for a controlled split.

Bake the loaf

Bake in the preheated oven for 30–35 minutes. The top should be deep golden brown and the internal temperature should read 190–200°F (88–93°C) when tested with an instant-read thermometer in the center.

Optional steam

For a slightly crisper crust, place a shallow pan of hot water on the bottom rack of the oven during the first 10 minutes of baking.

Cool and serve

Cool

Remove the loaf from the oven and immediately unmold onto a wire rack. Let cool completely, at least 1 hour, before slicing to allow crumb to set.

Store

Store cooled slices in a bread box or wrapped in a cloth and then plastic at room temperature for up to 3 days, or freeze sliced for up to 3 months.