Prepare the brown rice according to package instructions and set aside.
Season the chicken breast with salt and pepper, then grill or pan-sear until it reaches an internal temperature of 165°F.
Bring a small pot of water to a boil, carefully lower the egg, and simmer for 6.5 minutes for a jammy yolk.
Transfer the egg to an ice bath immediately, then peel and slice in half.
Slice the cooked chicken into bite-sized strips.
In a small jar, whisk together the extra virgin olive oil, lemon juice, dried oregano, salt, and pepper to create the dressing.
Dice the cucumber into small, uniform cubes.
Assemble the bowl by placing the warm brown rice at the base.
Top the rice with the sliced chicken, drained tuna, sardines, and diced cucumber.
Place the soft-boiled egg halves on top and drizzle the entire bowl with the lemon-herb dressing before serving.