This parsley sauce recipe is made of fresh parsley, butter, English mustard, milk, and flour
2 tablespoons/25 grams butter
2 tablespoons/20 grams all-purpose flour
1 1/2 teaspoons English mustard, optional
1 cup/250 milliliters milk, more as needed
1 handful fresh flat-leaf parsley, chopped
Sea salt, to taste
Freshly ground pepper, to taste
Steps to Make It
Gather the ingredients.
In a medium-sized saucepan, melt the butter over medium heat.
Stir in the flour and mustard (if using). Stir thoroughly to form a thick paste. Cook gently for 2 to 3 minutes more, watching the heat to ensure the paste does not burn. This will cook off the taste of raw flour in the finished sauce.Gradually whisk in the milk. Bring to a boil, lower the heat, and simmer for 5 minutes, frequently whisking to make sure there are no lumps. The sauce should be quite thick but still pouring consistency. If too thick, add a little more milk.Add the fresh parsley and stir well. Season with a good pinch of sea salt and a few black pepper grinds. Taste and add more as needed.
Keep the sauce warm, on low heat, until needed. If keeping sauce warm for more than 15 minutes, laying a piece of buttered parchment paper on the surface will prevent a skin from forming. If a slight skin does form, whisk thoroughly over heat, and it should disappear.
Circular piece of parchment paper placed on surface of parsley sauce in saucepan
Add finely chopped chervil or tarragon and a teaspoon of freshly squeezed lemon juice. This variation is great with fish.
If serving with boiled or baked ham, reserve some of the cooking liquor and make the sauce with half milk and half stock.
Stir in 2 tablespoons finely grated Parmesan cheese and serve over cooked vegetables au gratin.