Prep Pasta: Heat a 3-quart pot of salted water on the stove until it comes to a boil.
Make Dressing: Meanwhile, in a small bowl of measuring cup with a pour spout, add 2 tablespoons of olive oil, lemon juice, salt, and pepper. Whisk and set aside.
Cook Pasta: When the water comes to a boil, add pasta. Set a timer for pasta (according to the time on the package) for the kind of pasta you're using. When there are about 4 minutes left for the pasta to cook, add the frozen peas.
Saute: While the peas cook, heat the remaining 1 tablespoon of olive oil in a Dutch oven or large pot. On medium heat, saute the garlic and onion until soft and translucent.
Add Pasta: When pasta is al dente, drain it and add it to the onions in the Dutch oven/pot. Turn off the heat. Add the tuna and mix.
Finish Pasta: Add the herbs, mix, and then drizzle the dressing. Add Parmesan cheese and give a final mix.
Serve and enjoy!