Lighter Beef Stoganoff

Ingredients

• 1/2 (16 ounce) package whole wheat fettuccine or linguine
• 1 teaspoon olive oil
• 1-1/4 pounds top sirloin steak, cut crosswise into 1/4-inch-thick slices
• 1 small yellow onion, chopped
• 12 ounces sliced white mushrooms
• 1 cup less-sodium beef broth
• 1 tablespoon Dijon mustard
• 3/4 teaspoon kosher salt
• 1/4 teaspoon ground black pepper
• 2 tablespoons all-purpose flour
• 3/4 cup low fat plain yogurt