Creamy Pasta Primavera

Add pasta to a large pot of boiling water and cook 10 minutes. Add squash, asparagus and carrots and cook 8 minutes or until pasta and vegetables are tender. Drain and place in a large serving bowl. Meanwhile put flour in a large skillet. Slowly whisk in milk until blended, taking care to get into corners of skillet. Bring to a boil over medium-high heat, stirring often. Reduce heat to low and simmer 3 to 4 minutes, stirring constantly, until sauce thickens slightly. Remove from heat, whisk in sour cream, mustard, lemon juice, salt and pepper. Pour over pasta mixture and stir to mix and coat. Sprinkle with cheese.