Heat the olive oil in a pot over medium heat. Add the ground beef and cook until brown, about 3-5 minutes. Use a spoon to break up any large pieces while it's cooking.
In the meantime, add the roughly chopped carrots, celery, pepper, onion, and parsley to a food processor or blender. Pulse until you get a veggie mush.
Add the veggies to the beef and cook until most of the moisture is absorbed, about 3-5 minutes. Stir in the garlic, oregano, salt, and pepper. Add the can of tomatoes with their juices.
Use your spoon to gently break up the tomatoes and incorporate them into the sauce. Reduce heat to low and let it simmer for 20-30 minutes.
Enjoy warm over pasta or veggie noodles.
Storage and reheating: Keep in an airtight container in the fridge for 5-7 days. Or divide into containers and store in the freezer. Thaw in the fridge before reheating over the stove.Substitutions or additions: Feel free to add more veggies, like zucchini, summer squash, other types of peppers, and more.