Preheat oven to 425℉, line a large rimmed baking sheet with parchment paper or foil. Place cauliflower in center of pan, toss with the oil and taco seasoning. Roast for 25-30 minutes, stirring once halfway through, or until cauliflower is tender and a rich golden brown.
While the cauliflower roasts, make the lentils. Heat a medium size sauce pan over medium heat, add the olive oil, followed by the onion, saute 3-5 minutes or until translucent. Add the garlic and saute 30 seconds. Add the tomato paste, taco seasoning, adobo sauce, lentils and vegetable broth. Bring to a boil, reduce to a simmer and cover loosely with a lid. Simmer for 15-25 minutes, or until lentils are just tender. Add extra splashes of vegetable broth as needed during cooking to make sure the pan doesn't run dry. Drain any remaining liquid, taste and adjust seasoning.
Make the creamy chipotle sauce by smashing the chipotle in a small bowl with a fork until finely minced, then stir in the Greek yogurt or sour cream, mayonnaise and lime juice. Taste and adjust seasoning with salt and pepper.
When the lentils and cauliflower are ready, add the cauliflower to a large bowl (or the lentil pot if it will fit) with the drained lentils. Add in chopped cilantro and lime juice, stir to combine. Taste and adjust seasoning if desired.
Warm tortillas in the microwave or on the stove and keep warm in foil, or a tortilla warmer. Serve taco filling immediately with your favorite taco toppings. We used thinly sliced radish, queso fresco cheese, cilantro and avocado.