Preheat your grill to medium direct heat, aiming for around 400°F (204°C). Ensure the grill grates are clean.

Using a sharp knife, butterfly the flank steak by slicing it horizontally, creating a pocket for your stuffing.

In a medium bowl, combine olive oil, minced garlic, cilantro, parsley, salt, black pepper, and red pepper flakes. Stir until well blended.

Spread the herb mixture evenly across the surface of the opened steak, then layer quartered hard-boiled eggs and sliced bell peppers.

Carefully roll the flank steak tightly like a jelly roll, securing it with butcher's twine at equal intervals.

Generously season the exterior of the rolled steak with salt and pepper.

Place the stuffed flank steak on the preheated grill and grill for about 4-5 minutes on each side, aiming for a total cook time of 20 minutes.

Once cooked, remove the steak from the grill and allow to rest for about 15 minutes.

After resting, slice the steak into even portions to serve.