That does sound good & nice that they are made ahead.

Here's a recipe that I use that is good too:
1/2# small mushrooms, cleaned and sliced
1/4 tsp tarragon
1/2 tsp sugar
2T tarragon vinegar
6T olive oil
1/2 tsp dry mustard
Mix all ingredients and let marinate covered for 24 hours.
RL`

These recipes sound good. How long do the mushrooms last in the fridge?

In my house, not very long at all.

Oh! You mean how long would they last? Haven't a clue.

Here's my favorite, an adaptation of Piquant Mushrooms Potthoff---which is basically the recipe posted by Iris Gal:

Piquant Mushrooms

In a large nonreactive skillet combine 3/4 cup apple cider vinegar, 1/2 cup olive oil, 1/4 cup water, 2 tablespoons sugar, 2 tablespoons tamari, 1/2 teaspoon oregano, 5 peppercorns, 2 cloves, 1 bag leaf and one garlic clove, split.

Bring to boil and add up to 2 pounds small mushrooms, trimmed, and simmer them, covered, 5 minutes. Let the mushrooms cool in the marinade to room temperature and remove and discard the garlic.

Transfer the mixture to a nonreactive container and let the mushrooms marinate, covered and chilled, for at least 3 days.

Garden Lad,
Yes, that's the same recipe I use. Just added a couple more cloves. I think it's an excellent one.

Mst ~~ At our house they were eaten within a week, two at most. I think Roselin's recipe with its greater oil-vinegar ratio would be a better long term (a month?) keeper.

Iris, can't tell you........they don't last that long. They are good just to eat as is or in salads.

Roselin, I love tarragon so eager to find some nice mushrooms to try your recipe.
I'm going to hide them just for me . . . . . . . . . . . . . . . . . . . . . . . . . . . maybe they'll last a day?