In a medium skillet, melt the butter with 1
Tbs. of the oil over medium heat. Add the
breadcrumbs and cook, stirring often, until
golden-brown and toasted, about 4 minutes;
transfer to a plate. Stir 1 Tbs. of the cheese
into the breadcrumbs, and season with 1/2 tsp.
salt and 1/4 tsp. pepper.
In a food processor, combine the basil,
walnuts, preserved lemon, lemon juice, and
garlic, and pulse to combine. With the machine
running, pour in the remaining 1/2 cup oil
until the mixture is finely chopped. Transfer
to a large bowl, and stir in the remaining 1/4
cup cheese, 3/4 tsp. salt, and 1/8 tsp. pepper.
Meanwhile, bring a large pot of well-salted
water to a boil. Add the pasta, and cook
according to package directions. Reserve 1/2
cup of the cooking water, and then drain the
pasta. Transfer the pasta to the bowl with the
pesto, and toss to coat. Add tablespoonfuls of
the cooking water as needed to loosen the
sauce. Divide the pasta among four bowls, and
garnish with the breadcrumbs and torn fresh