Instructions

1. To make the slow-roasted beef tenderloin, the day before you want to serve this dish, start preparing beef. Trim off any silverskin and discard, then generously sprinkle beef all over with salt and pepper. Truss tenderloin by tying pieces of kitchen twine all down tenderloin in 1-in (2.5 cm) intervals.
2. Line a rimmed baking sheet with parchment and top with an ovenproof rack. Place tenderloin on rack and refrigerate, uncovered, for a minimum of 4 hours and up to overnight.
3. When ready to cook tenderloin, position 1 oven rack in middle of oven and a second oven rack about 6-in (15 cm) away from broiler. Preheat oven to 225 F (110 C).
4. While oven preheats, remove tenderloin from refrigerator and let sit at room temperature.
5. Transfer tenderloin, still on rack-lined baking sheet, to middle rack of preheated oven. Roast until internal temperature reaches about 10 degrees below your desired final Fahrenheit temperature (or about 5 degrees below if measuring in Celsius). For medium-rare, look for an internal temperature of 130 F (54 C). Start checking internal temperature of tenderloin with an instant-read thermometer after 2 hours in oven, though it may take up to 3 hours depending on thickness of tenderloin.
6. Once tenderloin is finished roasting, remove from oven and turn on broiler. Brush tenderloin with a thin layer of grapeseed oil and discard parchment from under rack. Place tenderloin, still on rack-topped baking sheet, on upper oven rack under broiler. Use tongs to turn tenderloin every 10 to 20 seconds until nicely browned on all sides, about 2 minutes total. Remove roast from oven and set aside to rest for 20 to 30 minutes.
7. Once meat has rested for at least 20 minutes, cut off twine and discard. Slice tenderloin crosswise into 1-in (2.5 cm) thick rounds, using twine marks to guide you. Arrange on a serving platter and drizzle with some Pomegranate Chermoula Sauce. Serve remaining sauce alongside.
8. To make the pomegranate chermoula sauce, in bowl of a food processor fitted with steel blade attachment, combine parsley, cilantro, garlic, coriander, red pepper chili flakes, ginger, lemon zest, lemon juice and pomegranate molasses. Pulse until just combined and herbs are roughly chopped. With food processor running, drizzle in olive oil, stopping to scrape down sides of food processor as needed, until oil is incorporated and sauce still has some texture to it. Taste and adjust seasoning with salt. Transfer to a serving bowl and stir in pomegranate arils. Store in an airtight container in refrigerator for up to 4 days.