In a large skillet over medium-high heat, heat 3 tablespoons of lard. Add the onion and bell pepper; sauté for 5 minutes, stirring constantly.

In a small bowl, whisk together the flour, salt, sugar, mustard, and cayenne; add to the onion and pepper, mixing well until moistened. Cook for 3 minutes, stirring constantly. Gradually pour in the milk, whisking constantly with each addition; bring to a boil. Lower the heat and stir in the corn and egg; cook for 5 minutes, stirring constantly. Remove from the heat and let cool for 10 minutes.

Preheat the oven to 400°F. Grease a 2-quart baking dish with lard and set aside.

When the vegetable mixture is cool, divide it evenly, spoon into the 4 pepper halves (about ½ cup per pepper half), and place the peppers in the prepared dish. Sprinkle the panko crumbs and paprika on top of the stuffed peppers and dot with the remaining 1 tablespoon of lard.

Bake for 20 minutes, until the peppers are heated through. Serve immediately.

Note: If you don't have access to lard or are averse to cooking with it, substitute butter.