Chop the broccoli and red onion. Slice grapes in half.
Combine lemon juice, Greek yogurt and sugar.
Toss together pasta, broccoli, red onion, and grapes. Pour dressing over the top. Toss until well coated. Chill until ready to eat (the longer the better).
Top with pecans just before serving. Serve with extra grapes and sliced pears.