Bring a large pot of water to a boil. Add a generous pinch of salt and cook ravioli just to al dente, according to package directions. When there are about 2 minutes left in the cooking time, first scoop about 1/2 cup of the cooking water out into a liquid measuring cup, then add peas to the boiling water and continue to cook. Drain ravioli and peas together; set aside.

While the ravioli is cooking, warm olive oil in a large skillet over medium heat. Add tomatoes and cook for 2-3 minutes, just until a few are starting to burst.

Add pesto to the skillet along with a splash of the reserved pasta water. Warm for 2-3 minutes, stirring often. Add more pasta water, a small splash at a time, until the sauce is thinned out to your desired consistency.

Stir in the lemon juice, followed by the drained ravioli and peas. Stir well to combine, then sample and season with salt and pepper to taste.

Serve right away, with fresh-grated Parmesan, red pepper flakes, and fresh basil on top if desired.