Bring a large pot of water to boil, salt it. Add the pasta and cook until aldente. Drain.
While the pasta is working, in a large skillet, heat a drizzle of olive oil over medium heat. Add the chorizo and cook until crisp, 2 to 3 minutes. Transfer to a paper towel lined plate.
In a medium saucepan, over medium heat add the shallots and garlic and cook until tender about 5 minutes. Whisk in the flour and whisk in the sherry. Stir in the chicken broth andmilk and cook until thickened; season with pepper. Stir in the cheese. Fold in the peas and pimientos.
Drain the pasta, toss with sauce and top with chorizo and parsely.