
Preheat oven to 400 degrees. Place the ciabatta slices on a cookie sheet, drizzle them with olive oil (approximately 1/8 to 1/4 cup) and sprinkle with salt. Place sheet in oven until slices are lightly toasted but not brittle, approximately 6 to 8 minutes. Remove ciabatta slices from sheet and set aside to cool.
Add 1/4 cup olive oil to a wide saute pan on medium-high heat. When the oil begins to smoke, add the porcini in one layer. Adjust the heat to medium and saute, turning, until evenly brown, approximately 3 to 5 minutes. (If you are using shiitake and portobello mushrooms, you may need to add additional olive oil to prevent sticking; cooking time may be as long as 8 to 10 minutes.)
Place the browned porcini in a large salad bowl. Add the shallot. Cover with plastic wrap and allow mushrooms to cool to lukewarm.
When ready to serve, crumble the ciabatta into bite-sized pieces into the bowl. Add the lemon juice, radishes and herbs. Season to taste with salt, pepper and up to 1/4 cup additional olive oil if desired. Toss and serve.