Place a rack in the center of oven and preheat to 425°F. Spray a baking sheet with non-stick spray; set aside.
In a large saucepan or soup pot over medium-high heat, add water; bring to a boil. Very slowly add baking soda a little at a time, being careful not to let water boil over pan; stir constantly to dissolve. Once it has dissolved, reduce heat to medium-low and keep water at a simmer.
Cut pizza dough into 4 equal pieces and roll each piece into a rope about ½-inch thick. Cut each rope into 1½-inch long pieces.
Working in 3 or 4 batches, drop pieces of dough into simmering water and gently stir to ensure they are completely submerged, making sure they don’t stick together. Allow dough to sit in the water for 30 seconds; remove them with a slotted spoon and place on prepared baking sheet.
Brush each pretzel piece with beaten egg white and sprinkle with coarse salt. Bake for 15 minutes or until nicely browned. Serve with mustard.
Nutrition Information Per Serving:
Calories: 187 (Calories from Fat: 18); Total Fat: 2g (Saturated Fat: 0g); Protein: 7g; Total Carbohydrates: 35g (Dietary Fiber: 1g; Sugars: 3g); Cholesterol: 0mg; Sodium: 319mg