Heat 1 tablespoon olive oil in a skillet on medium heat. Cook until the onions start to brown and caramelize, at least 10 minutes. If you have time, let the onions go until they are nice and caramelized.
Start cooking the pasta according to package instructions after the onions have been cooking for a few minutes.
Add the peas to the onions, along with another tablespoon olive oil and the tarragon and marjoram. Stir to combine, and cover the skillet. Lower heat to cook on medium low for about 5 minutes.
When the pasta is done to your liking, drain it, then toss immediately with the remaining tablespoon of olive oil onion/pea mixture. Next stir in the cheese, salt and pepper to taste. Plate and serve, passing additional cheese at the table.