Cut the eggplant into 2.5 cm / 1-inch cubes and toss with 1 tsp salt in a colander. Let it sit for 15 minutes to draw out moisture, then pat dry with paper towels.
Heat 2 tbsp olive oil in a 26 cm / 10-inch dutch oven or tagine pot over medium-high heat. Sear the eggplant in two batches, 4 to 5 minutes per batch, until golden on most sides. Remove and set aside.
Add the remaining 2 tbsp oil to the pot. Add the onion and cook for 5 minutes until soft. Stir in the garlic, ginger, cumin, coriander, paprika, cinnamon, turmeric, and chili flakes, and cook for 1 minute until fragrant.
Pour in the crushed tomatoes and vegetable broth, scraping up any browned bits from the bottom of the pot. Bring to a simmer.
Return the seared eggplant to the pot along with the chickpeas. Reduce the heat to low, cover, and simmer for 25 to 30 minutes, until the eggplant is fork-tender and the sauce coats the back of a spoon.
Stir in the maple syrup and lemon juice. Taste and season with salt and pepper.
Spoon the tagine over couscous or into bowls. Top with chopped cilantro and toasted almonds, and serve hot.