Wash, trim and peel two bunches rainbow carrots, pat dry and set aside.
Using a large heavy bottom saute pan over high heat, add grapeseed oil, wait until smoking hot.
Carefully add six small or four medium carrots at a time, sear until you see light caramelization on all sides.
Remove from pan and set aside using a folded paper towel.
Once all carrots are roasted and set aside, clean pan with paper towel and turn heat to medium-low.
Next, add both cumin seeds and coriander seeds to dry pan and toast until aromatic. About three minutes.
Add orange juice, light brown sugar, and Kosher salt.
Reduce on medium heat for three minutes then add carrots.
Continue to reduce until orange juice has a nappe consistency. Turn off heat.
Mount in butter, tarragon, and parsley. (Be sure to gently swirl pan around while mounting butter).
Place carrots in roasting pan and drizzle on brown sugar glaze. Roast in oven at 350 degrees for 10 minutes or until glaze starts to caramelize.