Put a layer of pepper on the tri-tip, trying to cover it completely.
Grill the meat over low heat about 15 minutes per side.
While the meat is cooking, blend 10.5 oz of strawberries in the blender with water and set aside.
Cut the remaining strawberries into small cubes and set aside.
Put strawberry smoothie, vinegar and sugar in a pot. Allow to reduce for 10 minutes and remove from the heat. Add diced strawberries and set aside until serving.
