Garlic Bread Topping
In a food processor, combine the bread, garlic and lemon zest. Pulse to obtain coarse breadcrumbs.
In an Iron Handle Skillet over medium heat, melt the butter. Add the breadcrumbs and cook, stirring, until nicely toasted, about 4 minutes. Season with salt and pepper. Remove from the heat and let cool. Add the herbs and Parmesan. Toss to combine and adjust the seasoning. Set aside.
Pasta
Fill a 6.7 L Round Dutch Oven with water and season generously with salt. Bring to a boil. Add the pasta and cook until very al dente. Remove 1 cup (250 ml) of the pasta cooking water and set aside.
Drain the pasta. Toss with a drizzle of olive oil and set aside. Rinse out and dry the Dutch Oven.
In the French Oven, melt the butter over medium-high heat. Add the pancetta and leek. Cook until golden, about 8 minutes. Add the garlic and red pepper flakes. Cook for 1 minute.
Add the wine, chicken broth and reserved pasta cooking water. Season with salt and pepper. Bring to a simmer.
Whisk in the mascarpone, parmesan and herbs. Let simmer for 5 to 8 minutes or until slightly thickened. Add the crab, asparagus, fennel and artichokes. Season with salt and pepper. Simmer until the vegetables are tender, about 5 minutes.
Add the pasta and lemon juice. Cook for 2 minutes, stirring to coat the pasta in the sauce. Adjust the seasoning. Remove from the heat.
In a bowl, toss the arugula and tomatoes with a drizzle of olive oil. Season with salt and pepper to taste. Add to the pasta and toss to combine. Garnish with the garlic bread topping.
Note
If the bread you have on hand is not stale, you can dry it out in an oven preheated to 300°F (150°C) for 10 minutes.