Peas and Cheese Tortellini

I pulled this from Rachael Ray's magazine. Sorry there is no date or page number.

1 pound frozen cheese tortellini
1 cup frozen peas thawed (I used more than a cup last time)
2 tablespoons butter (I made this with some fake spread like promise or smart balance and it didn't work out too well , I had to add some oil, so I'd say use real butter or margarine)
5 scallions white and green parts thinly sliced separately (when I made this on vacation I only had red onion--i just sliced it really small and it tasted good)
2 tablespoons flour
1 2/3 cups milk (I used 1% Horizon and it was good)
salt and pepper
1/3 grated parm cheese (i used the standby green can but the photo shows real grated parm cheese like flakes)

In a large saucepan of boiling salted water cook tortellini until al dente. drain

Meanwhile add peas, butter and scallion whites to another large saucepan cook over medium for 2 minutes. whisk in flour and cook, stirring for 1 minute. Gradually whisk in milk and boil. stir constantly. stir in scallion greens, salt and pepper.

Stir in tortellini and 1/3 cup cheese into sauce.

Serve with sprinkled parm cheese on top.