Bring a small pot of water to boil. Add lemon slices and boil for 2 minutes to reduce bitterness. Drain and pat dry.
Toss lemons with sage, sugar, and 1 tablespoon of olive oil. Place lemon slices, single layer, on a parchment paper lined baking sheet. Bake for 20 minutes, until lemons are no longer wet and start to slightly brown. Let cool.
In a large bowl, whisk together pomegranate molasses, allspice, and remaining 1 tablespoon of olive oil. Season with salt and pepper. Add cooled lemons, tomatoes, onion, parsley, mint, and spinach to bowl. Toss salad to coat.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2015/03/11/tomato-red-onion-and-roasted-lemon-salad/