Here are ten ideas for side dishes that go very well with flank steak: 1 – Potatoes or Mashed Potatoes. 2 – Tahini Roasted Broccoli. 3 – Roasted Carrots with Garlic. 4 – Curried Rice. 5 – Green Salad. 6 – Roasted Mushroom Salad. 7 – Sweet Potato Fries. 8 – Corn on the Cob. More items... 6 days ago