In the same skillet, heat oil over medium heat. Sauté pumpkin seeds, almonds, cinnamon stick, sesame seeds, raisins, apricots, and banana or plantain until golden and fragrant (about 5–7 minutes). Remove and set aside.
Char the vegetables: In the same skillet or under a broiler, roast tomatoes, tomatillos, onion, and garlic until blistered and softened.
Blend the mole: In a blender, combine soaked chiles (drained), sautéed seed/nut/fruit mixture, roasted vegetables, and enough water or stock to create a smooth, thick sauce. Blend thoroughly.
Simmer: Pour the mole into a saucepan, season with salt, and simmer over low heat for 20–30 minutes, stirring occasionally. Add more liquid as needed to reach desired consistency. Taste and adjust salt.