1. Melt the butter in a small skillet over medium-high heat. Add the scallions and garlic and cook, stirring frequently, just until softened, 2 to 3 minutes. Transfer to a medium-size mixing bowl.

2. Add the artichoke bottoms, prosciutto, basil, Parmesan, and Jarlsberg to the scallions and toss to combine. Sprinkle with the lemon juice and pepper. Bind the mixture with the mayonnaise and refrigerate at least 1 hour.

3. Meanwhile prepare the peppers: Preheat the oven to 400° F. Stem and seed each pepper, then cut into chunks about 2 × 1½ inches. Place the peppers in a single layer in a large, shallow baking dish. Drizzle with the olive oil and vinegar and sprinkle with salt and pepper. Roast the peppers 15 minutes, stirring once halfway through the cooking time. Remove from the oven and let cool.

4. When ready to serve the hors d’oeuvres, preheat the broiler. Mound about 2 teaspoons of the artichoke mixture onto each pepper wedge. Arrange in rows on baking sheets and broil 3 to 4 inches from the heat until puffed and bubbly, about 2 minutes. Let cool a few minutes, then transfer to a serving tray and pass with plenty of cocktail napkins.