For the vinaigrette: Pulse the cocoa nibs in a spice grinder until finely ground, 4 to 5 pulses.
Combine the ground cocoa nibs and the olive oil in a 1-quart saucepan and heat on low until warm and fragrant, 2 to 3 minutes. Turn off the heat.
Add the vinegar, shallot, salt, and red pepper flakes, and let sit for about 25 minutes.
Transfer to a jar, twist on the lid, and shake like crazy.
Toss lettuce with vinaigrette to taste. Divide dressed lettuce between 2 serving dishes. Arrange remaining salad ingredients over the lettuce. Serve with any remaining vinaigrette on the side.