Creamy Rosemary Mushroom Sauce (For Toast, Steak, Chicken or Pasta)

A delicious vegetarian rosemary mushroom sauce packed full of umami flavour thanks to a special, tongue-twisting ingredient. Eat on toast, meat, or pasta.

I started cooking this recipe when I was a uni student on a tight budget that didn’t stretch to include meat.

While not the cheapest vegetable in the market (fungi, but you know what I mean), mushrooms do make a tasty and more economical substitute for meat.

The original recipe from an old book included white wine, but wine was also beyond my budget, so I left it out and have been cooking it without wine since.

The recipe is not only tasty and easy to make, but it’s also super versatile. I share the different ways to serve it below.

Ingredients and Cost

Starting with a base of fried mushrooms and rosemary, this recipe builds flavour by adding Dijon mustard and Worcestershire sauce, then finishing it with sour cream for creaminess with a hint of tang.

While mushrooms have plenty of umami flavour on their own, Worcestershire sauce takes this dish to another level. However you pronounce it, it adds a depth of flavour that transforms the dish.

The cost per serve for this dish on toast is $2.46 and to buy all the ingredients from scratch is around $18.35 Australian (August 2022) with leftover mustard, bread, Worcestershire, and sour cream. Prices will fluctuate depending on the season and the cost of the mushrooms.

This cost also includes dried rosemary, but if you grow rosemary (an easy herb to grow), the cost of the rosemary is practically zero.

How to Serve this Sauce

This sauce makes a great vegetarian meal on its own, served on some toast, crusty bread, mashed potato, or soft or grilled polenta.

It’s also great on top of steak, chops, roast chicken thighs, and chicken breast. You can even wrap them in a crepe for a very retro meal.

We sometimes do a combined chicken and vegetable tray bake, but instead of marinating the chicken in pesto or other rubs, we cook it naked and top it with this mushroom sauce.

You can also turn this into a pasta sauce; see how below.

How to Turn Mushroom Rosemary Sauce into a Sauce for Pasta

Turn this into a pasta sauce by making it, well, saucier.

You have two options here. One involves white wine; one doesn’t.

If you want to use white wine, add about half a cup when you add the Dijon mustard and Worcestershire sauce. Stir it and let it simmer for a couple of minutes to reduce slightly, concentrating the flavour.

Then add in about one cup of cream. Stir until warmed through, then add your cooked pasta and toss to combine. Serve with a grating of parmesan cheese and a good grind of fresh black pepper if you like.

For the non-wine version, add one to one and a half cups of cream when you add the mustard and Worcestershire. Simmer on low for a few minutes to thicken slightly. Taste and add a splash more Worcestershire if your taste buds say it needs it.

Making Ahead, Storing, Reheating

This sauce can be made ahead and stored in the fridge for up to two days. Transfer to an airtight container and let cool slightly before storing in the refrigerator.

Reheat very gently, so the sour cream doesn’t split.

This sauce does not freeze well.

Using Up the Leftovers

Leftover mushroom sauce can be eaten in any of the ways listed above – I love it on toast.

Use leftover sour cream in baking instead of milk, as in these berry muffins. Other ideas include:

• Stroganoff
• Onion dip
• Corn relish dip
• On nachos
• On burritos like these or these.

To use up leftover mushrooms, you can add them to:

• stroganoff
• breakfast burritos
• mushroom risotto
• mushroom carbonara
• mushroom soup
• silverbeet and mushroom pie

The mustard and Worcestershire last for ages in the fridge or pantry and can be used to flavour a wide variety of dishes.