Melt a tablespoon of real butter in a cup of milk. It isn't a perfect substitution, but it should work reasonably well.
Clarification:
Adding butter to milk as a substitue for buttermilk will not work. Contrary to its name, buttermilk has no butter in it; it is actually very low in fat. The best subtitution for buttermilk is a teaspoon of lemon juice or vinegar to each cup of milk. Since buttermilk has a higher acid content than "sweet milk", the addition of an acid will result in a substitution extremely close to that of buttermilk.
Simply add the lemon juice or vinegar and stir, then let stand a few minutes for the milk to "curdle", and it will look, taste and work pretty much the same as commercial buttermilk.
It can be done, but it's not the best. The texture will be different, and the taste will be extremely off.
The best substitute for sherry vinegar in a recipe is red wine vinegar or apple cider vinegar.
salt
Doubtful this would work. Much different ingredient. Oil works well, Canola or Olive is the best for your health.
To substitute arrowroot for cornstarch in a recipe, use a 1:1 ratio and mix the arrowroot with a small amount of cold liquid before adding it to the recipe to prevent clumping.
One highly recommended buttermilk fudge recipe is to combine buttermilk, sugar, butter, and vanilla in a saucepan, bring to a boil, then cook until it reaches the soft ball stage. Remove from heat, add nuts or other desired ingredients, beat until creamy, then pour into a pan to set.
One popular recipe using Gold Medal self-rising flour is for Southern-style buttermilk biscuits. This recipe combines the flour with buttermilk and butter to create light and fluffy biscuits that are perfect for breakfast or as a side dish.
To substitute olive oil for vegetable oil in a recipe, use a 1:1 ratio. This means you can replace the same amount of vegetable oil with olive oil in the recipe.
To substitute evaporated milk for regular milk in a recipe, you can mix equal parts water and evaporated milk to achieve a similar consistency.
The best substitute for white wine vinegar in a recipe is either apple cider vinegar or rice vinegar. Both of these options can provide a similar level of acidity and flavor profile to white wine vinegar.
To substitute butter for oil in a baking recipe, use a 1:1 ratio. Melt the butter and measure it in the same amount as the oil called for in the recipe. This will help maintain the texture and flavor of the baked goods.
To substitute fresh basil for dried in a recipe, use three times the amount of fresh basil as the recipe calls for dried. For example, if the recipe calls for 1 teaspoon of dried basil, use 3 teaspoons of fresh basil. Chop the fresh basil finely before adding it to the recipe for the best flavor.