Preheat oven to 450 degrees F. Line a baking sheet with parchment paper or grease.
Add water and mustard to a free standing mixer. Add yeast, flour, salt, and sugar. Using your dough hook, knead on low until ingredients are incorporated, about 4 minutes.
Increase mixer speed to medium, kneading for 3 minutes until dough comes together, but still a little tacky. Place dough in a large greased bowl. Cover bowl with plastic wrap or a damp towel.
Let dough rise in a warm area for 1 hour, or until doubled in size.
Turn dough onto a lightly floured surface. Knead once or twice and divide the dough evenly into 8 pieces. Roll each piece into an 18-inch rope. Fold ends over each other into a pretzel shape. Place on prepared baking sheet. Sprinkle with coarse salt.
Bake 15-20 minutes until golden brown, but still soft. Serve with additional mustard.