To prepare the tomato jam, in a pot over low heat, warm the olive oil. Add the shallots and cook, stirring occasionally, until translucent.

Add the tomatoes, vinegar, brown sugar, mustard seeds, rosemary, red pepper flakes and salt and bring to a simmer. Cook over low heat, stirring frequently, until almost all of the liquid has evaporated.

Let the tomato jam cool to room temperature, then cover and refrigerate until ready to use.

To prepare the cheese sauce, in a large saucepan over medium heat, melt the butter. Whisk in the flour and mustard and cook, whisking constantly, until no visible flour remains. Add the onions and bay leaves and cook, whisking constantly. Whisk in the milk and paprika until smooth, then simmer for 20 minutes. Remove from the heat.

In a bowl, whisk the eggs until blended. Add about 1 cup of the sauce to the eggs and whisk until combined. Pour the egg mixture into the pan with the remaining sauce and whisk until combined. Whisk in the cheddar and Gruyère cheeses, and season with salt and pepper. Let the sauce cool. Remove and discard the bay leaves.

Working in batches, transfer the sauce to a blender and puree until smooth.

If not using right away, transfer the sauce to a container, cover and refrigerate until ready to use.

To prepare the herbed bread crumbs, preheat the oven to 325°F.

In a small bowl, stir together the panko and melted butter until coated. Spread the panko out on a baking sheet. Transfer to the oven and bake, stirring every 5 minutes, until the panko is golden brown.

Let cool, then stir in the parsley and salt. Store at room temperature until ready to use.

To finish the dish, bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Drain and transfer to a large bowl.

Toss the pasta with 1 cup of the lightly warmed cheese sauce and the grated cheddar and Gruyère cheeses. Sprinkle with some herbed bread crumbs, top with a spoonful of tomato jam and serve.