1 Fill a large saucepan with salted water; bring to a boil.2 Add linguine; cook until pasta is firm-tender, about 10 minutes. Drain, reserving 1/2 cup cooking liquid; set aside.3 Transfer pasta to a large serving bowl; cover to keep warm.4 Meanwhile, in a large skillet over medium-high heat, heat olive oil until hot. Add onion; cook, stirring occasionally, until crisp-tender, about 5 minutes. 5 Reduce heat to medium; add mushrooms and garlic; cook, stirring occasionally, until mushrooms are tender and just release their liquid, about 6 minutes.6 Stir in roasted red peppers, salt and black pepper; cook until heated through, about 1 minute.7 Add the reserved cooking liquid; pour over linguine. Stir in croutons and Parmesan cheese. Serve immediately.