Start by cooking the pasta in salted, boiling water in a large pot for 10-12 minutes, according to package directions.
While the pasta is cooking, peel and chop the onion.
While the pasta is cooking, add some oil or butter to two skillets (there will be 3 pans to clean up, but it's worth it) and set the two skillets over a stovetop that has been set to medium heat.
Add the onion to one of the skillets and sauté it for about 5 minutes. Move the onion to one side of the skillet. Then add some eggs to the other side of the same skillet and scramble the eggs.
Chop and sauté the veggie sausage patty or chicken sausage in the other skillet. When done, set aside.
Rinse and chop up the bell pepper or tomatoes.
When the pasta is ready, drain it and add the warm pasta to a large bowl. Add in the sautéed onion, scrambled eggs, and cooked sausage. Then add in the chopped bell pepper or tomatoes. Mix all the ingredients so they are combined.
Season with salt and pepper to taste.
Slice or cube the avocado and add it to the breakfast pasta.
Drizzle the onion chili oil or chili oil on top.
Sprinkle some chopped fresh parsley over the pasta, and this bowl of protein-packed deliciousness is ready to enjoy!