Add the olive oil and butter to a large saucepan. Add the carrots, celery and onions and sauté until the vegetables are tender. Add the ground beef and cook until browned, breaking up the meat.
Add the jar of marinara along with salt and pepper to taste along with the red pepper flakes if adding and cook until the sauce has thickened, about 30 minutes. Add the heavy cream.
Cook your pasta according to package directions. I don't drain, I add my pasta to a separate separate skillet or large pan that I have added some of the sauce, adding more sauce along with a little of the pasta water, until all of your pasta is completely coated. Cook for just a minute or so, adding more pasta water if needed until the pasta has combined with the sauce. Serve immediately with parmesan cheese and fresh herbs like Italian parsley or basil. Enjoy!
