Dried corn, called hominy, gives this shrimp chili its substance.
Heat a grill until hot, or turn on broiler. Roast jalapeno until completely charred, turning, 5 to 6 minutes. Transfer to a small bowl; cover tightly with plastic. Let sit 10 minutes. Using your hands, rub off most of charred skin, rinsing hands frequently under cold running water. Slice in half; remove seeds.
Place a 10-inch skillet over high heat. When hot, add the tomatillos, and cover. Cook, turning occasionally, until slightly softened and black in spots, about 8 minutes. Transfer to the bowl of a food processor; add the green chiles, roasted jalapeno, roasted garlic, cumin, black pepper, and cloves. Puree until smooth, 20 seconds.
Coat a 3-quart saucepan with cooking spray, and place over medium heat. When hot, add onions, and cover. Cook, stirring occasionally, until onions are soft and golden, about 10 minutes. Uncover, and add chili mixture; cook, stirring, until thick, about 15 minutes. Add 3 1/4 cups vegetable stock; let simmer, uncovered, 20 minutes. Add hominy, simmer 5 minutes more. Add shrimp, and turn the heat to low.
Place parsley, cilantro, raw garlic, and remaining 1/4 cup stock in bowl of food processor. Process 2 minutes. Stir puree into chili; cook 1 minute more. Divide among six bowls, garnish with radishes, and serve.
To roast garlic, wrap head in foil and place in a 400-degree oven for 45 minutes.