Tuna Noodle Skillet

1 Tbsp. canola oil
1 large onion, finely chopped
4 C. water
4 C. uncooked medium egg noodles
8 oz. sliced fresh mushrooms
2 5-oz. cans solid white tuna in water, drained
16 oz. jar Alfredo pasta sauce
1 C. seasoned croutons, coarsley crushed

In a 12 in. nonstick skillet, heat oil over medium-high heat. Add onion. Cook 2-3 min., stirring frequently, until softened.
Stir in water and noodles. Cover; heat to boiling. Boil 4 min.
Stir in mushrooms, tuna, and pasta sauce. Reduce heat to medium; simmer uncovered 4-6 min. or until mushrooms are tender, sauce has slightly thickened and noodles are tender.
Remove from heat; let stand 5 min. Just before serving, top with croutons.