Heat the olive oil in a large pot over medium heat. Add the diced onion and cook for 5 minutes until softened. Stir in the minced garlic and cook for 1 minute more.
Add the cumin, cinnamon, and smoked paprika. Stir for 30 seconds until the spices smell fragrant.
Pour in the lentils, diced tomatoes, and 4 cups vegetable broth. Season with salt and pepper. Bring to a boil, then reduce heat and simmer uncovered for 25 minutes until the lentils are tender.
While the stew simmers, bring 2 cups water to a boil in a separate saucepan. Stir in the couscous, cover, and remove from heat. Let it sit for 5 minutes, then fluff with a fork.
Toast the pine nuts in a dry skillet over medium heat for 3 to 4 minutes, shaking often, until golden.
Spoon the couscous into bowls. Ladle the lentil stew over the couscous. Top each serving with toasted pine nuts and chopped parsley.