Sandwich Buns:

1. Lightly grease a medium bowl with vegetable oil or cooking spray and set aside. 
2. In a bowl of a stand mixer fitted with the hook attachment, add the flour and salt and whisk to combine.
3. In a small saucepan heat the milk to 95℉ (35℃). 
4. In a separate, small bowl, whisk together the warm milk and yeast. Then incorporate the sugar. Set aside. 
5. With the mixer on low speed, add the milk mixture and 2 eggs to the flour. Mix until a rough dough forms, scraping down the bottom and sides of the bowl with a rubber spatula, as needed. 
6. Add the butter and knead to fully incorporate for at least 5 more minutes until the dough is smooth and supple. 
7. Turn the dough out onto a work surface and shape into a tight ball. Place the dough into the prepared, greased bowl. Cover with plastic wrap and allow to rise at room temperature for 1 hour or until doubled in size. 
8. Punch down the dough and divide into 8 even-sized pieces, about 95- 105g each. Shape each piece of dough into balls and place onto a lightly greased baking sheet. Cover with greased plastic wrap and allow to rest at room temperature for 7 minutes. 
9. Roll the dough balls into a 7” (18cm) long demi-baguette shape, and place 6 of them, evenly spaced apart, onto a parchment-lined baking sheet. Lightly press down on the buns to flatten. Cover with greased plastic wrap, and proof for 20 minutes at room temperature. Repeat with the remaining 2 pieces of dough on a separate baking sheet.
10. Preheat the oven to 375℉ (190℃).
11. In a small bowl whisk together the remaining egg and water until evenly combined. Brush the proofed buns with the egg wash and generously sprinkle the tops of each with sesame seeds. Optionally, to achieve the split-top, you can score the tops of the buns, straight down the middle, vertically, using a razor at a 45° angle. 
12. Bake in the oven for 16-18 minutes or until golden brown. 
13. Brush the buns with melted butter, if desired, and place on a cooling rack to cool completely to room temperature. 

‍Mayo:

1. In a medium bowl, whisk together the egg yolks, mustard, sugar, a pinch of salt, garlic, and white pepper, if using. 
2. To incorporate the oil easily, add it to a squeeze bottle. 
3. While constantly whisking, slowly and gradually add the oil, drop by drop until an emulsification starts to develop.Then gradually increase the stream of oil, whisking the whole time, until the mayonnaise is thick and glossy. 
4. Whisk in the creme fraiche and lemon zest. Season to taste.
5. Store in the refrigerator until ready to use. 

‍Fried Chicken:

1. Using a meat grinder or food processor, finely round the chicken and pork. Transfer to a medium bowl 
2. Season the ground meat with salt, garlic powder, nutritional yeast, black pepper and onion powder and mix until well-combined. 
3. Divide the meat into four equal-sized portions and form into oblong-shaped patties, placing each onto a lightly greased baking sheet. Cover with plastic wrap and freeze for 15 minutes to solidify the fats and thus, the shape.
4. Fill a 7-8 quart (6.6-7.5L) heavy bottomed pot just over halfway with oil. Heat to 350℉ (175℃). Line a baking sheet with a cooling rack and place that next to the hot oil.
5. In a medium bowl, add the flour. 
6. In a second, medium bowl, beat the eggs and water. 
7. In a third medium bowl, add the panko breadcrumbs. 
8. Remove the chicken patties from the freezer. Gently toss each patty in the flour to fully coat on both sides. Shake off the excess flour and dip into the egg wash to completely coat, there should be no bald spots. Finally, add the patties into the panko and press down to ensure the panko crumbs are adhered all over.
9. Fry the patties, 2-3 at a time, in the hot oil for 4-6 minutes until crispy, golden brown and cooked through to 165℉ (74℃). Place on the prepared cooling rack to drain of excess oil and season with salt or mushroom seasoning powder.

‍Assembly: 

1. Slice a bun in half lengthwise and toast in a hot pan with melted butter until crispy.
2. Spread a generous spoonful of mayonnaise on the bottom half.
3. Top with a fried chicken patty.
4. Place a couple leaves of fresh butter lettuce on top of the patty.
5. Spread mayo on the top half of the bun and crown the sandwich.