Rub the fish with olive oil. Sprinkle with salt and pepper, then lightly pat the rounded side of the fish with mustard seeds. Grill over hot coals on an oiled grill, or a grill basket, seed side down first, about 7 minutes. Turn and grill an additional 8 minutes, until the flesh is firm and opaque. Serve with lentil salad.

Place the lentils in a medium pan with the garlic and bay leaf and cover with 1½ cups cold water. Bring to a boil, lower the heat, and simmer for 5 to 8 minutes, or until soft. Do not overcook, or the lentils will be mushy. Drain and remove the garlic and bay leaf Spread the lentils on a cookie sheet to cool.

Combine the oil, vinegar, cumin, salt, and pepper in a small cup.

Mix the lentils, onion, arugula, and parsley together in a bowl. Toss with the dressing. Garnish with tomato wedges.