What kinds of vegetable-based sides would you serve with this?

roasted asparagus and or a green salad

Hm. It's a pretty big plate of food and i am not a big side dish gal but i would say some broccoli rabe cooked with some garlic or green beans and almonds
asparagus with lemon and parmesan.

This recipe sounds to me like a meal in itself. I would probably serve warm French bread with it to mop up the sauce, and I think steamed spinach would be a good side dish.