In a large cast iron skillet on the stove, melt the butter over medium heat. Once melted, stir in the green beans and cook, stirring continuously, for about 5 minutes. You want the beans to be tender yet still crisp.

Stir in the garlic, the crushed red pepper, and salt. Stir over medium heat for another 1-3 minutes, until the garlic is browned but not burned. Put the beans into a serving dish and top with the Parmesan cheese.