Rinse the dry lentils under cold water and place them in a pressure cooker with 2.5 cups vegetable stock. Cook on high pressure for 9 minutes, then allow pressure to release naturally for 10 minutes before opening. Alternatively, bring lentils and stock to a boil in a pot, then reduce heat and simmer for 20-25 minutes until tender but not mushy. The lentils should hold their shape while being fully cooked through. While the lentils cook, you'll have time to prepare your aromatics for the next step.
Heat a large pan over medium heat with enough oil to coat the bottom. Add the finely diced red onion and cook for 4-5 minutes, stirring occasionally, until softened and beginning to caramelize at the edges. Mince the garlic cloves and add to the pan, cooking for just 30 seconds until fragrant—this short timing prevents the garlic from burning and turning bitter. Add the fennel seeds, Italian seasoning, and smoked paprika, stirring constantly for about 1 minute to toast the spices and release their oils into the oil base. I like to toast the spices this way because it deepens their flavors significantly compared to adding them raw.
Add the tomato paste to the spiced aromatics and stir continuously for 1-2 minutes, allowing it to caramelize slightly in the pan. This caramelization builds depth and removes any raw, tinny flavor. Fold in the chopped sun-dried tomatoes and the red pepper flakes, stirring until everything is well combined. The sun-dried tomatoes will soften slightly as they warm through, helping to distribute their concentrated umami flavor throughout the base.
Once the cooked lentils from Step 1 are ready, drain them in a sieve (rinsing is optional—I skip rinsing to retain the starch, which helps create a naturally creamy texture). Add the drained lentils to the pan with the tomato-spice mixture and stir to coat evenly. Pour in the vegetable stock and bring the mixture to a gentle simmer over medium heat. Simmer for 10 minutes, stirring occasionally, to allow the lentils to absorb the surrounding flavors and the sauce to develop a cohesive taste.
Reduce the heat to low to prevent the cream from breaking or curdling. Pour in the cream and sprinkle the parmesan cheese over the lentil mixture, stirring gently and continuously until the cheese is completely melted and the sauce becomes silky and creamy. Tear the fresh basil by hand and stir it in just before serving—tearing rather than cutting prevents bruising and keeps the basil flavor bright and fresh. Let the finished dish rest for 5 minutes off heat to allow all the flavors to meld together beautifully.
Divide the creamy lentils into bowls and serve immediately while warm. Garnish each portion with extra fresh basil if desired, and serve with lemon wedges on the side for guests to squeeze over their bowl according to preference. The acidity from the lemon brightens the rich, creamy flavors and adds a final layer of complexity to this elegant dish.