In a large bowl, activate yeast by adding it to warm water and add oil and sugar and let stand for 5 minutes.
Stir in the egg and salt.
Add the whole wheat flour and mix well. Then gradually add the last cup of bread flour until a soft dough forms. If it's still very sticky, add a bit more flour until it's nice and soft.
Turn onto a floured surface and knead until smooth and elastic, 3-5 minutes.
Divide the dough into 8 equal pieces and shape each into a ball.
Place 3 inches apart on lightly greased baking sheets. Cover and let rise for 15-20 minutes.
Brush each bun with egg and then sprinkle on sesame seeds or toppings of choice.
Bake buns for 7-10 minutes or until golden brown. Let cool on wire rack.