In a large pan, heat the butter over medium heat. Add the leeks and cook, stirring occasionally, for 12 minutes, until they sweat and become tender and sticky. Add the garlic and lemon and cook for 1 minute. Remove the leek mixture from the heat and combine with the grits in a large pot and keep warm.
In the same large pan, heat the olive oil over medium-high heat.
While the oil is heating, in a large mixing bowl, toss the shrimp with the black pepper, salt, and cumin until well coated.
Place the shrimp and the peppercorns in the pan and cook the shrimp for 2 minutes on each side (4 minutes total), until it has become opaque (time may vary depending on the size of the shrimp).
Remove from heat and serve the shrimp on top of the leek and lemon grits, garnishing with the goat cheese.