Blend all pesto ingredients, aside from the oil, in a food processor fitted with the “S” blade.

While the machine is running, slowly add the oil through the feeder and blend until a fine paste forms.

Cut mushrooms into halves or quarters.

Heat oil in a frying pan and sauté mushrooms until soft. Discard any additional juice, or reserve for use in a later recipe (see tip).

Add one tablespoon of pesto to the pan, or more as desired, and toss just to coat.

Remove from heat and serve warm or room temperature.