In a big saute pan over medium-high warmth, warmth 1/4 cup of the olive oil till it shimmers. Add the cleaned leeks and 1/4 teaspoon of the salt and prepare dinner, stirring sometimes, till tender, about 5 minutes. Add the mushrooms and prepare dinner, stirring, till they launch their liquid, darken and soften, 4 to five minutes. Switch the combination to the salad bowl and let cool.