Add oil to saucepan. Saute onion and garlic until translucent. Add Italian seasoning. Add the tomato paste and cook 3 minutes. Add the sausage and break it up until it's in as small pieces as possible, works great with a potato masher. Add the crushed tomatoes. Bring to a simmer and cook 15 minutes season with salt and pepper. Meanwhile cook the lasagna noodles in boiling salted water and drain and let cool down a bit.