Pasta Shells with Portobello Mushrooms and Boursin Sauce

Bahan-bahan (4 porsi)

• 1 tablespoon butter
• 1 tablespoon olive oil
• 16 ounces portobello mushrooms ((stems removed, caps halved and cut into ¼-inch slices))
• 1/2 teaspoon salt
• 1¼ cups canned low sodium chicken or vegetable broth
• One 5.25-ounce container Boursin cheese
• 16 ounces asparagus
• 12 ounces medium-sized pasta shells