Creamy Shrimp Grits with Prosciutto

For grits: Bring chicken stock, whipping cream, butter and garlic to boil in heavy large saucepan. Gradually whisk in corn grits. Return to boil, whisking constantly. Reduce heat to low. Simmer uncovered until grits thicken, whisking often, about 15 minutes. For shrimp: Melt 1/4 cup butter in heavy large skillet over medium-high heat. Add shallots and garlic and saute until tender, about 4 minutes. Add shrimp and saute 2 minutes. Using slotted spoon, transfer shrimp to large bowl. Add white wine to skillet and boil until reduced to glaze, about 5 minutes. Add drained diced tomatoes and half of prosciutto and simmer until slightly thickened, about 2 minutes. Add parsley, chives and sauteed shrimp and simmer until shrimp are warmed through, about 2 minutes. Thin sauce with some of reserved tomato juices, if desired. Season to taste with salt and pepper. Spoon corn grits into shallow bowls. Top each serving with shrimp-prosciutto-tomato mixture, dividing equally. Garnish with remaining prosciutto strips and serve immediately.