Preheat oven to 425 degrees.
In a small bowl, mix lemon zest, garlic and salt and pepper.
Put tenderloin in a dish and rub mixture into meat.
Heat a pan on medium-high heat. When pan is warm, add a drizzle of olive and sear the tenderloin on all sides until they're golden brown. Be careful not to over cook.
Transfer tenderloin to an oven safe pan and cook for 10-15 mins max or until the internal temp of the roast is 140. Again, be careful not to overcook.
Let roast sit for a few minutes to reabsorb juices and carryover cook.
Squeeze fresh lemon juice on top and garnish with cilantro.