Heat the olive oil in a skillet over medium heat. Cook and stir the garlic and jalapeno pepper in the hot oil until fragrant, about 5 minutes; add the heavy cream and bring the mixture to a simmer. Reduce heat to low. Stir the Parmesan cheese and rosemary through the mixture; continue cooking until the cheese is completely melted, about 5 minutes more. Season with salt and pepper to serve.