You can force it to flower by giving it a longer dark period somehow. Or you could let it veg through spring and naturally go into flower when the days get short enough.
I've never tried to force a plant in the middle of reveg back into flower but, I'd say it's probably best to veg it long enough that your leaves look normal. My experience with revegging comes from taking cuts off flowering plants and it is a slow process to get to the point of pointed, serrated, 5+ blade leaves. Especially the Vanilla Frosting I have. She loves to throw 3 blade leaves if she isn't happy. But once they get to that point, their growth really starts to take off.