Set sous vide machine to 55C/131F.
Salt and pepper the tri tip to taste. Put the tri tip in a freezer bag with crushed garlic, and remove the air through a vacuum sealer or the displacement method. Drop tri tip in the bath for 6 hours.
Remove bag from bath. Take tri tip out of the bag, pat dry and season with salt and pepper to taste. Heat pan on high and add oil. Sear for 1 to 2 minutes on each side.
Slice and serve tri tip topped with fresh chimichurri or your favorite BBQ sauce and enjoy!