Heat olive oil in a large pot over medium heat until shimmering. Add diced onion and cook for about 5 minutes until translucent and slightly golden around the edges.
Add minced garlic and grated ginger to the pot and sauté for 1 minute until fragrant, being careful not to let the garlic brown or burn.
Stir in all the dry spices (cumin, coriander, cinnamon, turmeric, and cayenne) and cook for 30 seconds to bloom the flavors. You’ll know they’re ready when your kitchen fills with an amazing aroma.
Add the pumpkin cubes and stir to coat them evenly with the spice mixture. Cook for about 3-4 minutes, allowing the edges to slightly caramelize.
Pour in the diced tomatoes with their juice, followed by the vegetable broth. Stir in the drained chickpeas and harissa paste, then bring the mixture to a gentle boil.
Reduce heat to a simmer, cover partially with a lid, and cook for 20-25 minutes or until the pumpkin is fork-tender but not falling apart.
Stir in the honey or maple syrup to balance the acidity and spices. Taste and adjust seasonings as needed.
Add the chopped spinach and half the cilantro, stirring until the spinach wilts, about 1-2 minutes.
Finish with a squeeze of fresh lemon juice and remove from heat. The brightness of the lemon will elevate all the flavors in the stew.
Let the stew rest for 5 minutes before serving to allow the flavors to meld. Serve in bowls topped with remaining cilantro, a dollop of yogurt if using, and a sprinkle of toasted pumpkin seeds.