Heat oven to 220C/200C fan/gas 7. Halve the peppers through the stalk, then cut out and throw away the seeds. Sit the peppers snugly, cut-side up, in a casserole dish, or two if needed. Halve any larger tomatoes, then divide them, the bread chunks, garlic and chorizo between the dishes.
Drizzle over the vinegar, then the olive oil, and season with pinches of sugar, sea salt and ground black pepper. Bake for 30 mins, covered, until the peppers are tender and collapsing a little. Remove, uncover and cook for a further 30 mins. Leave the peppers to cool a little, then scatter with parsley, if you like, and spoon onto plates, scooping out any extra juices. Serve with crusty bread for mopping up the juices.