Preheat the oven at 400 F (200 C). Prepare a baking pan by covering it with aluminum foil.
Place the sweet potato cubes in a bowl and add 1 tbsp olive oil and toss until all the pieces are coated with the oil. Sprinkle a pinch of fine salt and a some found black pepper. Spread on the pan in one layer and roast for about 30 minutes until soft but not falling apart.
In a pot place the lentils with a bay leaf and about 2 cups of boiling water. Simmer for 20-25 minutes until soft, but not mushy and drain. Set aside.
In a small bowl you can prepare the dressing by mixing 2 tbsp extra virgin olive oil, 1 tbsp vinegar and tsp honey. Mix well until the dressing thickens. Set aside.
Assemble the salad by placing the lentils and sweet potatoes in a bowl, toss gently, add ½ of the dressing and toss. Add the mandarins, sprinkle with the almonds and feta (if using), drizzle the rest of the dressing and finish with some parsley, thick sea salt and freshly ground pepper. Enjoy!