Pour 6 tablespoons boiling water on the oats in a small bowl. Let sit until softened and cooled to lukewarm temperature.
Stir the 4 tablespoons warm water, wheat flour, sugar, and yeast in a bowl. Let sit until frothy.
Add white flour, salt, and softened, cooled oats to the wheat mixture. Stir to combine. Dough should be tacky, but not sticky or wet.
Knead dough on lightly floured surface for 5 minutes. Form into two oblong 6-inch hoagie shapes. Place loaves on very lightly greased pan, cover, and let rise for 40 minutes.
Score the tops of each loaf. Bake at 375 degrees for 15-18 minutes until golden brown and done.
Cool before cutting.