Rub the bell pepper with olive oil and bake at 400 degrees F. until brown.
Place the charred bell peppers in a zip lock bag to steam.
Season the tuna with salt and pepper.
In a sauté pan, heat canola oil.
Sear the tuna to medium rare. Set aside.
Peel and seed the bell pepper, cut into strips.
Sauté the shallots until clear and add chicken broth, balsamic vinegar and olive oil, bring to a boil.
Place watercress and bell pepper in a bowl and toss with hot liquid.
Place under or over tuna.