Warm the olive oil in a pan then sauté the onions until just turning golden brown. Use a few drops of water instead of the olive if you want to keep this oil-free.
Add the garlic and cook for one minute more.
Add the tomatoes, chili, herbs, nutritional yeast, balsamic vinegar, salt & pepper and stir well. Leave to simmer on low while you cook the pasta.
Cook pasta in a large pan of boiling water until just al-dente.
While the pasta is cooking, break the bread up roughly with your hands and add to the bowl of a food processor or blender. Add 2 tablespoons of olive oil, garlic and nutritional yeast. Process until fine crumbs. Set aside.
Drain pasta then pour the sauce and stir well to combine.
Pour the saucy pasta into a large casserole dish, smooth the top a bit with a spoon, then sprinkle over the breadcrumb mixture evenly.
Bake for 20 – 25 minutes or until the crumb topping is golden and crunchy.
Leftovers can be reheated in a loose lidded container in the microwave or the oven.