Step 1In a medium saute pan, heat 2 tablespoons of olive oil over medium heat. Add the ginger, garlic and jalapenos and saute until the garlic is golden, about 4 minutes. Add the cardamom, turmeric and coriander and saute until fragrant, about 1 minute. Remove from heat.
Step 2Transfer to a blender, add the vinegar and blend well to combine. With the blender on low speed, add the remaining one-half cup of oil in a thin, steady stream, blending until well combined. (Makes 1 cup.)
Step 1Soak 8 bamboo skewers in water for at least 30 minutes. Toast the peanuts in a small nonstick saute pan over medium heat until golden, about 3 minutes. Transfer to a blender, add the masala, lime juice and salt, and puree until smooth.
Step 2Score the skin of the duck breasts in a diamond pattern. Heat a large saute pan over medium-high heat. Add the breasts, skin side down, and cook for 6 minutes to render the fat. Turn and cook for 2 minutes, but no longer -- the meat should be rare. Remove from the pan; allow to cool slightly. Cut each breast crosswise into 4 pieces.
Step 3Thread the duck, pears, onions, scallions and red peppers alternately onto the skewers, using two pieces of duck per skewer. Pour the peanut mixture into a wide shallow pan or baking dish. Add skewers and turn to coat. Marinate for at least 15 minutes and up to 2 hours.
Step 4Prepare a medium grill fire. If using a charcoal grill, bank the hot coals to either side. Place a drip pan beneath the cooking rack. Grill the skewers, turning frequently to avoid flare-ups and to cook evenly, until the duck is medium-rare, about 7 to 10 minutes. Transfer to a platter, tent with foil and let rest for 5 minutes. Serve.