If cooking lentils from dry, start this step before the sauce to let lentils cook while you prepare the rest.
For black lentils using Instant Pot: Combine lentils with salted water, cook on HIGH for 9 minutes, natural release 10 minutes.
For stovetop: Combine lentils with salted water and simmer for 20 minutes until tender but firm.
Heat sundried tomato oil in a large pan over low-medium heat.
Sauté diced onions until softened.
Add crushed garlic, cook 30 seconds until fragrant.
Add crushed fennel seeds, cook until aroma releases.
Add more oil, smoked paprika, Italian seasoning; cook on low until spices blend without burning.
Stir in tomato paste and chopped sundried tomatoes; cook until combined.
Turn off heat and set aside.
Drain cooked lentils in a fine sieve and rinse under running water until clear.
Add lentils to the pan, return to medium heat, stir well.
Pour in vegetable stock and bring to a simmer.
Cover initially, uncover for last few minutes to thicken sauce; simmer 10 minutes.
Stir in heavy cream, cheese, and chopped basil.
Heat on very low until cheese melts and basil wilts.
Cover and let rest 5 minutes to thicken.
Stir before serving.
Serve with lemon wedges for squeezing over.