In a large bowl or the bowl of an electric mixer, place the salt, sugar, yeast and 2 1/4 cups flour. Mix to just combine. Add the water and mix well, adding remaining flour, as needed, a bit at a time to form a soft, smooth dough that clears the sides and bottom of the bowl.

Knead the dough, by hand or machine, for about 5 minutes, until it is soft, smooth and quite slack. Lightly oil the dough and place it in a bowl, covered with plastic wrap. Let it rise for 40-60 minutes.

Preheat your oven to 475 degrees. Prepare two baking sheets by lining them with parchment paper or lightly greasing them.

Transfer the dough to a lightly greased work surface, and divide it into about four equal pieces. Roll each piece into a rope, about 1 inch in diameter. Allow the pieces to rest, uncovered, for 5 minutes. Cut each strip of dough into pieces, 1 to 1 1/2 inches in long.

While the dough is resting, bring the water and baking soda to a boil in a large pot or Dutch oven. Stir until the baking soda is dissolved. Drop the pretzel bites (about 15 at a time) into the boiling water and let boil for one minute.

Remove the dough from the boiling water with a metal strainer or slotted spoon, allowing all of the water to drain back into the pot.  (Instead of boiling, you can dip the pretzel bites in a mixture of 1 cup warm water and 2 tablespoons of baking soda). Allow pretzel bites to rest to rest, uncovered, for 10 minutes. Brush with beaten egg.

Bake one sheet at a time for 5-7 minutes or until the pretzels are golden brown.

Remove the pretzels from the oven, and brush them thoroughly with the melted butter. If desired, sprinkle with coarse salt. Pretzels can be reheated in the oven or microwave on low heat.

To make the honey mustard sauce, whisk together all the ingredients in a medium bowl. Serve with pretzel bites.