Heat oil in pan. Saute onions until tender. Add garlic and saute another 30 seconds. Add balsamic vinegar and continue heating for about 1 minute, stirring often.
Add the tomatoes, tomato paste, sugar, oregano, pepper flakes, basil, salt, and pepper. Simmer until sauce is thick, about 20 minutes. Stir often, then set aside.
Cook the lasagna noodles in 4 quarts of lightly salted water until they are al dente, about 8 minutes. Drain, rinse with cold water, and let cool.
Combine the ricotta, eggs, and parsley. Stir well and set aside.
Combine the mozzarella and gouda in a bowl. Set aside.
To assemble the lasagna, start with some tomato sauce on the bottom, then noodles, then ricotta mixture, then a little shredded cheese. Repeat this order twice. The last layer should be tomato sauce topped with a little cheese.
Bake the lasagna uncovered in a 350 degree oven about 40 minutes.