Add the milk, water, butter and honey to a small bowl and microwave until warm and the butter is melted, about 110-120 degrees. Alternatively, you can do this on the stove in a small pot.

Pour the milk mixture into the bowl of a stand mixer (or large bowl), then add in the yeast, egg and sourdough discard. Mix on low with the paddle attachment until everything is combined. Alternatively, you can do this all by hand.

Add the flour and salt. Mix again until a shaggy dough forms.

Switch to the dough hook attachment and knead on medium-low for 8-10 minutes until the dough is smooth but a little tacky. If your kitchen is warm or humid, you may need to add an extra 1-2 tablespoons of flour. You don't want the dough super sticky, but avoid adding too much extra flour, which will create heavy, dense buns. Once the dough rises, it'll be easier to work with.

Rub a little olive oil all over the dough ball in the bowl. Cover the bowl with plastic wrap and let rise in a warm place until doubled, about 30-60 minutes, depending on the temperature of your kitchen.

Punch down the dough to release the air, then divide into 12 pieces (each about 86 g). Shape each piece into a ball, creating surface tension, and place on two parchment lined baking sheets, about 2-3 inches apart. Cover and let rise until doubled in size, about 1 hour.

Preheat the oven to 375 degrees. In a small bowl whisk together the egg and milk. Brush the top and sides of the dough with the egg wash and sprinkle with sesame seeds.

Bake for 20-25 minutes until puffed and golden brown. Transfer to a rack to cool.