Your regular spaghetti with sauce, just that I cut the veggies instead of the regular pounding or coarse blending.
TIPS
1) Use lots of onions in order to have a balanced taste in the sauce. This is because when you put lots of bell pepper without compensating with onions, the sauce tends to taste bitter(ish).
2) The beef stock makes the sauce to be juicy, but skip it if you prefer a dry sauce. Adjust seasoning accordingly.
3) Cooking spaghetti with more water than needed gives very good result. It's moist (not dry). Just drain properly in colander and serve.