For the chicken: Preheat a cast-iron grill pan over medium-high heat. Drizzle the chicken with 2 tablespoons of the canola oil. Season with 2 teaspoons of the salt and 1 teaspoon of the pepper; drizzle with the remaining 4 teaspoons canola oil.
Place the chicken seasoned-side down on the grill. Season the side facing upwards with the remaining 2 teaspoons salt and 1 teaspoon pepper. Cook the chicken until golden-brown and the exterior has formed a crust, turning midway through to form the cross-hatch pattern, 3 to 4 minutes. (Note: the chicken is not being flipped, the same side is still on the grill.) Flip the chicken and repeat until the other side is golden brown, 3 to 4 minutes. The center of the chicken should be firm to the touch when poked and the meat thermometer should read 165 degrees F.
For the salsa verde: Combine the garlic and the anchovies on the cutting board. Put the parsley, chives and tarragon on the cutting board and coarsely chop to combine with the garlic mixture. Put the salsa mixture in a medium bowl and add the lemon zest. Add the red pepper and salt. Mix the herb mixture together while drizzling in the olive oil until thoroughly combined. Put the salsa in a serving bowl and set aside until the chicken is ready.