Preheat oven to 375ºF. Line a large sheet pan with parchment paper or foil. On the sheet pan, toss the sweet potatoes with 1 to 2 Tbsp. avocado oil (just enough to coat) and a generous pinch of salt. Arrange cut sides-down, place on the middle rack of the oven, and bake for 50 to 60 minutes, until the flesh is soft and caramelized.

In a large sauté pan or skillet, heat 1 Tbsp. oil over medium heat. Add shallots and cook until softened, about 3 to 4 minutes. Stir in garlic and cook 30 seconds, until aromatic. Stir in tomato paste, harissa, smoked paprika, and ground coriander; cook until the tomato paste deepens in the color and the spices bloom, about 2 minutes. Add lentils; stir to coat in seasonings. Pour in vegetable broth and season with ½ tsp. kosher salt and a few grinds of black pepper. Increase heat to bring mixture to a boil. Reduce heat and gently simmer with the lid slightly ajar until the lentils are tender and most of the liquid is absorbed, about 25 to 30 minutes.

In a small mixing bowl, combine tahini, lemon juice, and grated garlic; mix to combine. Gradually stream in 3 to 4 Tbsp. water, whisking constantly, until the mixture is smooth and thin enough to drizzle. Season to taste with kosher salt and cracked black pepper.

Once the lentils have simmered, remove lid and stir in kale. Cook, uncovered, for 2 to 3 minutes, stirring often, until the kale is wilted. Taste and season lentils with extra salt and/or black pepper, if needed.

Place two roasted sweet potato halves on each plate and use the prongs of a fork to gently fluff and open up some of the flesh. Generously spoon lentil mixture overtop and drizzle with lemony tahini sauce. Garnish with chopped fresh parsley and a few grinds of cracked black pepper.