Place the first 2 Tbsp. oil in a medium pot set over medium heat. Add the onion, poblano pepper and garlic and cook until softened, about 5 minutes. Mix in the chili powders, cumin, cinnamon, oregano and raisins and cook 1 minute more.
Mix in the tomato sauce, stock, water, peanut butter and cocoa powder and bring to a gentle simmer, adjusting the heat as needed. Partially cover the pot and gently simmer mole sauce 20 minutes, or until richly flavoured, aromatic and lightly thickened.
While the sauce simmers, preheat your barbecue or indoor grill to medium-high. Brush chicken with the second 2 Tbsp. oil; season with salt and pepper.
When the sauce has simmered 20 minutes, puree it in the pot with hand blender, or in a food processor or blender. Return sauce to a simmer, adding a bit more stock if you find it too thick, and then cover and reserve on low heat.
Now lightly oil the bars of the grill. Grill the chicken 3 to 4 minutes per side, or until cooked through. Plate the chicken, top generously with sauce, sprinkle with pumpkin seeds and enjoy.
Note: Poblano peppers are dark green, very mildly spicy and available in the produce department. If you can’t find it, try a small green bell pepper in this recipe. Chipotle chili powder is available in the bottled herb aisle. Shelled pumpkin seeds are available in the bulk food department. To toast, place them in non-stick skillet and set over medium heat 3 to 4 minutes.