Bring large pot of water to a boil. Add whole garlic cloves, lemon slice, bay leaves and lentils. Reduce heat and simmer for about 20 minutes. Drain and rinse with cold water. Remove garlic, lemon, bay leaves, and continue to allow lentils to drain in colander. Let cool completely.
Toast your almonds in a pan over medium heat watching and stirring often until they start to brown. Set aside to cool.
Whisk together oil, red wine vinegar, oregano, salt and pepper.
In a serving bowl combine cooled lentils, feta, cucumber, onion, parsley, arugula, tomatoes and dressing, stirring to combine. When ready to serve sprinkle with toasted almonds.