Peel and finely chop the onion. Trim and peel the carrot. Dice it. Trim and thinly slice the celery. Peel and grate or crush the garlic.
Heat 1/2 tbsp olive oil in a pan.Add the mince to the pan. Give it a good stir to break it up. Brown for 5 mins over a medium heat. Stir every so often.
Add the chopped veg to the mince. Season with salt and pepper. Cook and stir for another 5 mins till the veg is soft and glossy.
Add the garlic to the pan. Cook and stir for 1 min till it smells fragrant.
Tip in the tomatoes. Add 1/2 can water. Add 1 tsp of the dried oregano. Bring the bolognese sauce to the boil. Turn the heat down to low. Simmer for 30 mins till the sauce thickens. Stir every now and then.
While the sauce simmers, fill a pan with water. Add a pinch of salt. Cover. Bring to the boil. Add the spaghetti. Simmer for 8 mins till the spaghetti is cooked but not too soft. You want it to have a little bite.
Pop the leaves in a colander. Rinse them. Dry off in a salad spinner or pat dry with kitchen paper. Pop in a bowl. Drizzle with 1/2 tbsp olive oil. Season.
Drain the spaghetti. Taste the bolognese sauce and add more slat and pepper if you think it needs it. Toss in the spaghetti. Pick it up and drop it a few time sot mix it together. Serve with the salad and Parmesan cheese for grating.