Roasted Tuna Collar with Arugula Gremolata
For the Tuna Collar:
Brush a sheet tray with olive oil. Place the tuna collar on the tray, flesh side up, and season with the salt, pepper, and chili flakes. Scatter the lemon slices, thyme, and bay leaves evenly on top of the collars and drizzle with olive oil. Marinate for 3 hours in the refrigerator. Preheat the oven to 350°F. Place the butter in a few places on the collars and roast in the oven for 20 minutes.
For the Arugula Gremolata:
Combine the arugula, parsley, garlic, shallot, anchovies, lemon zest and juice, salt, and oil in a bowl and mix well.
To Assemble and Serve:
Place the Tuna Collar on a large platter. Top with the Arugula Gremolata, and garnish with pea tendrils, baby arugula, and cherry tomatoes.