Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain, reserving a ladleful of the pasta cooking water.
Meanwhile, heat a drizzle of EVOO in a skillet over medium-high heat. Add the bacon and brown to crisp up; transfer to a plate to drain.
Place the parsley, cheese, almonds and garlic in a food processor and pulse to finely chop. Pour in about 1/3 cup EVOO and process to form a thick pesto. Scrape into a large, shallow bowl with the tomatoes and onion; season with salt and pepper. Stir in the reserved pasta cooking water.
Add the pasta to the pesto mixture and toss with the lettuce and bacon.