Cook pasta“al dente” according to package instructions.
Meanwhile, cut grapes in half and chop scallions.
In a bowl combine mayo, lemon juice and minced garlic. Lightly season with salt and pepper.
Once pasta is cooked, drain. Return back to the pot. While pasta is hot, add cheese and mix. Add in scallions and grape, mix.
Add the dressing to the bowl and mix well.
Refrigerate covered for at least two hours or overnight.
Before serving, toss gently.