In a large mixing bowl, or stand mixer, dissolve the yeast in warm water. Whisk in the sugar, salt, minced onion, egg, and oil. Stir in the flour and knead for 7 minutes. Let rise for 30 minutes or until doubled.

In a small bowl, add 1 tablespoon of dry minced onion and cover with water to rehydrate. Set aside until you are shaping your buns.

Cut the dough into 8 equal pieces for large buns, 12 for small buns, and 16 for slider buns. Shape and place buns onto a cookie sheet about 2 inches apart.

Drain the water from the minced onions. Add 2 teaspoons of oil and mix with the hydrated onions.

Brush each hamburger bun with milk and then add a spoonful of the hydrated onion and oil mixture on top of each bun. Press the onion mixture gently on top of each bun.

Let the buns rise on the cookie sheet until tripled in size or the size of the hamburger buns you want.

Bake at 350 degrees F for 12-16 minutes on the middle or lower rack in your oven. Remove the buns when you achieve the level of golden brown you're after.