Place the cilantro, pine nuts, lemon juice, feta cheese, salt, and black pepper into the work bowl of a food processor, and pulse several times to mince the ingredients. Drizzle in 1/ 2 cup of olive oil with the machine running, and process until the pesto is a slightly textured paste. Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the tagliatelle pasta, and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta is cooked through, but still firm to the bite, about 8 minutes.

Drain well in a colander set in the sink.

Place the cooked pasta into a large serving bowl, and toss with the pesto. Drizzle a bit of extra- virgin olive oil over the pasta, and serve hot.