1Preheat oven to 400°F (200°C). Toss delicata squash with 1 tbsp olive oil, smoked paprika, cumin, cayenne (if using), salt, and pepper. Spread on a baking sheet and roast for 20-25 minutes, flipping halfway, until tender and lightly caramelized.
2While squash roasts, heat the remaining 1 tbsp olive oil in a medium pot over medium heat. Add red onion and sauté until softened, about 5 minutes. Add minced garlic and cook for 1 minute more until fragrant.
3Stir in rinsed lentils, vegetable broth, and diced tomatoes (with their liquid). Bring to a boil, then reduce heat to low, cover, and simmer for 25-30 minutes, or until lentils are tender and most of the liquid has been absorbed. Season with salt and pepper.
4Meanwhile, prepare the avocado-lime crema. In a small food processor or with a fork, mash the avocado until smooth. Stir in lime juice, Greek yogurt, and a pinch of salt. Blend or mix until creamy.
5Warm tortillas according to package directions (microwave, dry skillet, or oven).
6To assemble the tacos, spread a layer of avocado-lime crema on each warm tortilla. Top with a generous spoonful of spiced lentils, then add roasted delicata squash slices.
7Garnish with fresh chopped cilantro and serve immediately.
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