- To a small saucepan on medium-high, add lentils, diced onion, salt and 1 cup water and bring to a boil. Reduce to a simmer, cover and cook until lentils are tender, about 25 minutes. Drain and set aside to cool.
- Meanwhile, in a medium bowl, combine minced onion, olives, parsley, capers, vinegar and 2 tbsp oil; set aside.
- Brush top (skinless side) of fish with egg white. Press almonds evenly over top of fish. In a very large skillet on medium, heat remaining 4 tsp oil. Add fish, crusted side down, and cook until almonds are toasted, 2 to 3 minutes. Carefully turn and continue cooking until fish is cooked through, 3 to 4 minutes.
- Arrange arugula on plates or a platter and top with lentils. Arrange fish over lentils and spoon on olive mixture.
Related: Why Eating the Mediterranean Diet Makes Sense