The key to great mushrooms on toast is to cook the mushrooms down enough that they are condensed in flavour and texture. You can use one type or a variety. Not just for toast, you can use them in other places you need sautéed mushrooms such as with scrambled eggs, in tarts, through pasta etc.
Heat the butter or oil in a frying pan over a medium heat.
Add the mushrooms with the salt and sauté for 10 minutes until their moisture has evaporated.
You can stir though a handful of chopped herbs at the end of cooking such as parsley, chervil, marjoram, dill, tarragon, basil. If using oregano, thyme or rosemary they are best added sparingly and finely chopped or a whole sprig (which can be removed at the end) at the beginning of cooking.
For creamy mushrooms add a few tablespoons of creme fraiche, double cream, sour cream, mascarpone, Greek yoghurt or cream cheese and gently stir through and heat.
To make creamy mushroom sauce for steak etc sauté one or two garlic cloves with the mushrooms then add 150mls cream and simmer for about 10 minutes until thick (keep an eye on it, you don’t want to boil the cream) and season with freshly ground pepper and more salt if needed.
To make mushroom & red wine sauce for steak, roasts etc cook the mushrooms in oil then add 250ml of red wine, a sprig of thyme and boil down to reduce to half. Add any pan scraping from cooking the meat (you can loosen with a little boiling water. Season with salt and pepper. Stir in 30g butter if liked before serving.
Mushrooms love curry flavours, add a teaspoon of curry powder, freshly ground cumin and coriander or a handful of curry leaves at the beginning of cooking. You can stir in a can of tomatoes and a spoon of plain yoghurt for a quick mushroom curry.