In a Medium Bowl combine all the above wet ingredients, mix well to completely dissolve the mustard.
Add in brown sugar, salt, pepper and green onion.
Stir until brown sugar is dissolved.
Combine the marinade with the roasts in a large bowl or an extra large leak proof ziplock bag perfect for marinading.
Refrigerate overnight.
Preheat Grill to 350*.
Place Roast in Roasting Pans (I recommend the disposal ones for easy clean-up) and cover with aluminum foil.
Cook for 2 - 2 1/2 hours or until completely cooked.
Remove let sit for 5 minutes and then slice and serve.