Mix the yeast with two tablespoons of warm water. Let it stand until the yeast dissolves, about five minutes.
Mix lukewarm soymilk with melted butter, vinegar, sugar and salt.
Add the soymilk-butter-sugar mixture to the yeast in the bowl.
Add two cups of all purpose flour and the baking soda to the bowl and mix in a stand mixer with the dough hook attached, or using your hands. Continue to add more flour, a quarter cup at a time, until a smooth, supple dough forms. Continue kneading for a couple more minutes.
Form a smooth ball with the kneaded dough and place in an oiled bowl. Coat the top with oil. Cover with a tight lid or cling wrap and set aside in a warm spot for an hour.
After an hour the dough should have risen and doubled in size.
Knead the risen dough lightly and place on a floured surface. Roll the dough to about ½-inch thickness.
Use a 2-inch cookie cutter to cut out rounds from the dough. Roll up any scraps and cut out more rounds. I got a total of 12 rounds.
Use a chopstick or a straw to press lightly into the center of a round of dough, creating an indentation. Create similar indentations in all rolls.
Fold each disc over along the indentation, creating a half-moon shape. Press firmly on the edge with your finger to seal.
Place the rolls in an oiled, 13 by 9 inch baking pan. Cover loosely with a kitchen towel and set aside to rise in a warm spot.
Fifteen minutes before you are ready to bake the rolls, preheat oven to 425 degrees Fahrenheit/220 degrees Celsius. Generously oil a 13 X 9 inch baking pan.
After rising for an hour the rolls will be puffy and would have doubled in size. Brush them with some melted vegan butter and place in a preheated 425 degree oven. Bake 17 minutes or until golden brown on top.
Cool on a rack or serve warm.