Prep everything first: rinse and sort the lentils under cold water (remove any small stones or debris) — rinsing removes dust and helps them cook evenly. Peel and finely dice ¾ of the carrot and ¾ of the celery stalk; reserve the remaining carrot and celery for raw ribbons in the salad. Halve the onion: finely chop one half for the soup and thinly slice the other half for the salad. Mince the garlic.

If you started with dry lentils: bring the 4 cups (960 ml) of broth to a gentle simmer in a medium saucepan and add the lentils. Simmer 20–25 minutes until just tender but not falling apart — cooking them separately early ensures precise timing and a clean broth texture. If using 2 cups cooked lentils, skip this pre-cook and add them later to the soup (see step 6).

In a large heavy-bottomed pot or Dutch oven, heat the 1 tbsp olive oil over medium-high heat. Add the sliced turkey sausage in a single layer; let it brown without moving for 2–3 minutes, then stir and brown the other side. Browning (Maillard reaction) builds deep savory flavor and releases fond (browned bits) that will flavor the soup.

Remove about two-thirds of the browned sausage to a plate (you’ll add some back as garnish later) and leave the rendered fat and any fond in the pot. If your sausage is particularly lean and there isn’t much fat, add a small splash (½ tsp) of oil — you need some fat to sweat the vegetables and pick up the fond.

Reduce heat to medium. Add the chopped onion, carrot, and celery to the pot and a pinch of salt. Sweat them gently, stirring occasionally, for 6–8 minutes until softened and just starting to color. Sweating (rather than high-heat browning) softens the vegetables, releases their sugars and builds a sweet aromatic base for the soup.

Add the minced garlic, dried thyme, smoked paprika (if using) and black pepper; stir for 30 seconds to bloom the spices and release their aroma. If you pre-cooked lentils in step 2, add the cooked lentils now and proceed to step 8. If you pre-soaked/cooked the lentils in the broth in step 2, reserve that simmered mixture and add it now (including the cooking liquid) to the pot with vegetables and sausage.

Pour in the broth (if you haven’t already used it to cook the lentils) and add the bay leaf. Scrape the bottom of the pot with a wooden spoon to deglaze and lift any browned bits — that’s concentrated flavor. Bring to a gentle boil, then reduce to a steady simmer.

If you used dry lentils and haven’t added them yet, add the rinsed dry lentils to the simmering pot now. Simmer uncovered (or partially covered) for 25–30 minutes until the lentils are tender but still hold their shape. Stir occasionally to prevent sticking. Cooking time varies by lentil age; taste for doneness after 20 minutes.

When lentils are tender, taste and adjust seasoning with salt and pepper. For a thicker, creamier texture, use the back of a ladle or a potato masher to press 1–2 cups of soup against the side of the pot — this releases starch from the lentils and naturally thickens the broth without cream. Stir the reserved browned sausage back into the pot and warm through for 2–3 minutes.

Finish the soup with a final drizzle (1–2 tsp) of olive oil and remove the bay leaf. The finishing oil adds gloss and a silky mouthfeel that makes the soup feel more 'restaurant' in quality.

While the soup simmers, make the spinach salad: shave the reserved ¼ carrot into thin ribbons with a peeler, thinly slice the reserved ¼ celery and the remaining half onion. In a small bowl whisk together the extra 1 tbsp olive oil, 1 tbsp vinegar, a pinch of salt and a few grinds of black pepper. Toss the baby spinach with the raw vegetables and the vinaigrette just before serving so the leaves stay crisp.

To serve: ladle the soup into warm bowls, top with a few extra slices of the browned turkey sausage and an extra grind of black pepper. Serve the spinach salad alongside or in small plates as a bright counterpoint.

Store leftovers: cool the soup to room temperature, then refrigerate in an airtight container for up to 4 days (or freeze up to 3 months). The salad is best eaten fresh; if preparing ahead, keep the dressing separate and toss just before serving.