In a large mixing bowl, combine flour, sugar, yeast, and salt. Add melted butter and warm water, mixing until a shaggy dough forms.

Knead the dough on a lightly floured surface for 8-10 minutes until smooth and elastic. Alternatively, use a stand mixer with dough hook attachment for 5-6 minutes.

Place dough in a greased bowl, cover with a damp towel, and let rise in a warm place for about 60 minutes until doubled in size.

While dough rises, prepare the filling by combining crumbled feta, chopped herbs, minced garlic if using, and black pepper in a small bowl. Mix well and set aside.

Preheat oven to 425°F (220°C) and line two baking sheets with parchment paper.

Punch down the risen dough and divide into 8 equal portions. Roll each portion into a rope approximately 18-20 inches long.

Create a shallow channel along each dough rope and fill with feta-herb mixture. Seal the edges by pinching them together, then roll gently to smooth.

Shape each filled rope into a pretzel: form a U-shape, cross the ends over each other, twist once, then fold the ends down and press them onto the bottom of the U to secure.

Bring 8 cups of water to a boil in a large pot. Add baking soda carefully (it will bubble up). Reduce heat to maintain a gentle simmer.

Working with 2-3 pretzels at a time, gently lower them into the baking soda bath using a slotted spoon. Boil for 30 seconds, flip, then boil another 30 seconds.

Remove pretzels from water, allowing excess liquid to drain, and place on prepared baking sheets.

Brush each pretzel with beaten egg and sprinkle with coarse sea salt and additional fresh herbs if desired.

Bake for 15-18 minutes until deep golden brown. The pretzels should have a shiny, mahogany-colored crust.

Remove from oven and let cool on baking sheets for 5 minutes before transferring to a wire rack. Serve warm or at room temperature.