Butter an 8-by-10-inch shallow baking dish. In the skillet, melt the butter. Add the tomato and cook over high heat for 1 minute. Add the ramp greens and bulbs along with the cream and season with salt and pepper. Simmer over moderate heat, stirring gently, until the cream is slightly reduced, about 2 minutes. Transfer the contents of the skillet to the prepared baking dish. Sprinkle with the cheese and bake for about 10 minutes, until bubbling.