Prep and read the recipe first. Chop bacon, onion, carrots, celery, and garlic. Rinse lentils under cold water and pick out any debris.

In a large Dutch oven or heavy pot, cook the chopped bacon over medium heat until crisp and golden, about 6–8 minutes.

Remove bacon with a slotted spoon to a paper towel-lined plate and leave the rendered fat in the pot. Add olive oil if necessary.

Add the chopped onion, carrots, and celery to the pot. Sauté in the bacon fat over medium heat until the onions are soft and translucent, about 6–8 minutes, stirring frequently.

Stir in the garlic, smoked paprika, and cumin (if using) and cook for about 30 seconds until fragrant.

Pour in the rinsed lentils, canned diced tomatoes (with juices), and broth. Toss in the bay leaf and thyme.

Bring the pot to a gentle boil, then reduce heat to low, cover, and simmer until the lentils are tender, about 25-30 minutes for brown/green lentils.

Once lentils are tender, remove bay leaf and season with salt and pepper. Stir in most of the crispy bacon (reserve some for garnish).

For a creamier texture, use an immersion blender to pulse a third of the soup directly in the pot, or scoop 2 cups into a blender, puree and return to the pot. This step is optional.

Stir in spinach or kale if using and cook for 2-3 minutes until wilted. Finish with lemon juice or vinegar before serving.

Ladle into bowls, sprinkle reserved bacon on top, and serve with crusty bread.