Heat the oven to 220°C (428°F), slide a Dutch oven onto the top shelf, a lightly greased oven tray onto the middle shelf, and plates into a warmer drawer or on top of the oven to warm up.
In a medium-sized pot, heat the Heinz baked beans on the stove, stirring in our non-traditional addition of chilli powder to add warmth and flavour if you like. Once hot and bubbling, transfer the baked beans to the Dutch oven.
Heat a frying pan, griddle pan, flat grill plate or skillet, brush sparingly with the neutral cooking oil and fry the pork sausages until cooked and golden. Transfer the sausages to a cutting board and slice them into bite-size pieces. Pull out the Dutch oven, evenly distribute the sliced sausages, using a fork to push them beneath the surface of the baked beans, and slide the Dutch oven back into the oven.
Fry the bacon pieces until crispy (or done to your liking), then use a slotted spoon to scoop out the bacon, saving the bacon fat to cook everything else in. Transfer the bacon to the oven tray, sliding it back into the oven to keep warm.
Fry the mushrooms in the bacon fat, first drizzling a teaspoon of olive oil over them, and sprinkling on half the salt and pepper, frying the mushrooms on both sides until golden-brown. When done, transfer them to the oven tray with the bacon.
Drizzle another teaspoon of olive oil onto the sliced part of the tomatoes, sprinkle on some salt and pepper, place the sliced side of the tomatoes face-down on the pan or grill and fry for a few minutes until brown. Turn the tomatoes over to cook the other side for a few minutes until tender, then transfer them to the oven tray.
Fry the slices of black pudding for a couple of minutes each side, taking care so that they don’t break apart, and use a fish slice to carefully transfer the slices to the oven tray. At the same time, pull the Dutch oven out of the oven.
Use a clean small single-egg frying pan to fry the eggs one at a time until the whites are cooked and yolk remains soft and runny, carefully sliding each egg as cooked onto the baked beans in the Dutch oven.
Remove the oven tray and arrange each of the ingredients – the crispy bacon pieces, brown mushrooms, tomato halves, and black pudding slices – around the fried eggs. If not eating immediately, return the Dutch Oven to the oven to keep warm.
When ready to serve, sprinkle the chopped fresh flat leaf parsley leaves on top and serve at the table with buttered toast, salt and pepper, HP sauce, tomato sauce (ketchup) and chilli sauce, and optional sides such as potatoes fried in bacon fat and/or bubble and squeak.