Israeli Couscous Risotto with Squash, Radicchio, and Parsley Butter

INGREDIENTS

3 cups

1/2-inch cubes peeled butternut squash

1 cup

Italian parsley, packed fresh leaves

3 tsp

Lemon peel

Onion, chopped (2 1/2 cups), large

1 cup

Radicchio

3 cups

Chicken broth, low-salt

1 8.8 ounce package

Israeli couscous, toasted

6 tbsp

Butter

3/4 cup

Parmesan cheese