In a heavy bottom pot, bring cream, 3 cups water, and salt to boil. Add cornmeal and whisk together. Reduce heat and let thicken, about 20 minutes, whisking frequently. Add additional water if needed to get the right consistency.
In the meantime, melt 2 tablespoons butter in a large skillet until just starting to brown. Add garlic, leeks, and corn and cook until corn is slightly blistered. Transfer to a bowl.
In the same skillet, melt remaining two tablespoons butter. Once slightly browned, add shrimp and cayenne pepper. Once shrimp is slightly pink, stir in white wine. Cook until shrimp is done, transfer to bowl with vegetables. If there is remaining liquid in pan, pour into grits (the shrimp and wine flavor makes the grits even tastier).
Adjust salt and pepper to taste. Serve shrimp and vegetables on top of grits.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2014/08/20/summer-shrimp-grits/