Heat butter till it melts, add in the flour and stir well over low heat.
Add in the water gradually and bring to a boil. Mix in the rest of the ingredients and simmer until gravy is thick.
Use gravy as a topping for your mashed potatoes.
Note: To mash potatoes, simply boil the potatoes until they are done. Skin them and mash with a fork while they are still hot. Add some butter (or mayonnaise), milk, salt and pepper as you mash, to the consistency that you like. For best results, use potatoes that are suitable formashing like the imported Russet potato. In general, fluffy potatoes are better for mashing than waxy ones.