In a mixing bowl, combine warm water, sugar, and yeast. Let it sit for 5 minutes until foamy.
Add flour, salt, and chopped rosemary to the yeast mixture. Mix until a dough forms.
Knead the dough on a floured surface for about 5-7 minutes until smooth and elastic.
Place the dough in a greased bowl, cover, and let it rise for 1 hour or until doubled in size.
Preheat the oven to 450°F (230°C). Line a baking sheet with parchment paper.
Divide the dough into 8 equal pieces. Roll each piece into a long rope and shape into pretzels.
In a large pot, bring 10 cups of water and the baking soda to a boil. Boil each pretzel for 30 seconds on each side.
Place the boiled pretzels on the prepared baking sheet. Brush with beaten egg and sprinkle with coarse sea salt.
Bake for 12-15 minutes or until golden brown. Let cool on a wire rack before serving.