Soak Lentils: If using Spanish lentils, place them in a medium bowl, add cold water to cover by 1 inch, and let sit overnight in the refrigerator.
Drain and rinse.
Cook Base: Heat the olive oil in a soup pot over medium heat.
Add the onion and cook, stirring, until wilted and transparent (about 5 minutes).
Add the bacon and cook, stirring, until transparent (about 10 minutes more).
Add Lentils and Broth: Stir in the lentils, water, crushed tomatoes, parsley, bay leaves, salt, pepper, paprika, cumin, thyme, rosemary, vinegar, and the garlic.
Bring to a boil.
Reduce heat to low, cover, and simmer for 45 minutes until well blended.
Add Potatoes and Spinach: Add the potatoes, cover, and simmer for 15 minutes more or until they are tender.
Add the spinach, cover, and simmer for another 15 minutes until the flavors are well blended.
Finish and Serve: Squeeze the garlic flesh into the soup and discard the skin and bay leaves.
Serve hot.
Notes & Wine Advice
Wine Advice:Pair with a robust red wine such as a Rioja or Ribera del Duero