Dissolve one package quick-acting yeast in a half cup each of warm buttermilk and water with a tablespoon of sugar. When the yeast begins to work, add a quarter cup of vegetable oil and mix in alternately three cups white flour, half a cup of grated sharp cheddar and a quarter cup of fresh rosemary leaves. Knead until smooth, let rise for three hours, punch down and place in an oiled baking pan to rise until doubled. Bake in a moderate (350) oven until crisp and golden. Brush the top with butter just for the aroma.