1 pound sweet potatoes, peeled and cut into 1/2-inch pieces
1 clove garlic, peeled
Kosher salt
1 medium head cauliflower (about 2 pounds), cut into small florets
1 1/2 tablespoons plus 1 1/2 teaspoons extra-virgin olive oil, divided
Freshly ground black pepper
1/2 cup black lentils
3 tablespoons tahini
1 teaspoon ground cumin
1 teaspoon freshly squeezed lemon juice, plus more as needed
2 packed cups baby spinach leaves (about 2 ounces)
1/3 cup coarsely chopped fresh cilantro
2 tablespoons toasted pumpkin seeds