Step 1: Preheat your oven to 200°F (95°C) and place a baking sheet inside to keep cooked items warm. Gather all ingredients and set up your cooking stations.
Step 2: Place sausages in a large, cold frying pan or griddle. Turn heat to medium-low and cook for 15-20 minutes, turning regularly, until golden brown and cooked through. Transfer sausages to the warm oven.
Step 3: Add bacon to the same pan (or a separate pan if preferred). Cook over medium heat for 5-7 minutes, turning until crispy to your liking. Transfer bacon to the warm oven.
Step 4: In the same pan with residual bacon fat (add 1 tbsp olive oil if needed), add sliced mushrooms. Sauté for 5-7 minutes until tender and golden. Season with salt and pepper. Transfer mushrooms to the warm oven.
Step 5: In a small saucepan, gently heat the baked beans over low heat, stirring occasionally. Halve the tomatoes and place them cut-side down in the large frying pan (or another small pan) with a little olive oil. Cook for 3-5 minutes until slightly softened but still holding shape. Season. Keep warm.
Step 6: In the large frying pan (wiped clean if necessary, or use a fresh one) with 1 tbsp olive oil or butter, fry the black pudding slices for 2-3 minutes per side until crisp and heated through. Remove and keep warm.
Step 7: In the same pan, fry the eggs to your preference (sunny-side up with runny yolks is classic). Cook until the whites are set and the yolks are still liquid, about 2-3 minutes. Season with salt and pepper.
Step 8: While eggs are cooking, toast your bread. Butter the toast generously once done.
Step 9: Assemble individual plates with two sausages, two slices of bacon, a spoonful of baked beans, sautéed mushrooms, two tomato halves, a slice of black pudding (if using), and a fried egg. Serve immediately with buttered toast and your choice of sauces.