How to Make It
Preheat a water bath to 135°. Season the tri-tip steak with the salt. Transfer to a 1-gallon vacuum-pack bag and vacuum-seal. Submerge the bag in the water bath and cook at 135° for 1 hour.
In a bowl, mix the shallot with the lime juice; let stand for 10 minutes. Using a handheld mixer, beat in the butter, chipotle and cilantro at low speed until blended.
Light a grill or preheat a grill pan. Remove the steak from the water; let stand in the bag for 10 minutes. Remove the steak and pat dry. Brush the grill with oil and grill the steak over high heat, turning once, until browned and crusty, 2 minutes. Transfer the steak to a work surface; let stand for 5 minutes. Thinly slice the meat and transfer to plates. Serve the cilantro butter alongside.