Combine yeast, oil, milk, and water in a bowl with an electric mixer. Add salt and 2 cups of flour. Gradually add remaining flour until a soft dough forms. Knead for 3-4 minutes.
Transfer dough to lightly greased bowl. Cover with greased plastic wrap and let sit until doubled in size, about 1-2 hours.
Preheat oven to 425F. Portion dough into 16 pieces and place on lightly greased parchment or lightly floured counter. Roll each piece of dough into a round ball. Let sit for 15-20 minutes.
Bring water, sugar, and baking soda to a boil.
Pinch the bottom of each dough ball to form a pucker. Place 3-4 dough balls into boiling water at a time, leaving for 30 seconds to 1 minute per side.
Place boiled dough balls onto baking sheet lined with lightly greased parchment or silpat liner. Using sharp knife or razor, slice 2-3 cuts into top of each roll, about 1/4-inch deep. Lightly sprinkle dough balls with coarse salt.
Bake 20-22 minutes, until rolls are deep golden brown.