Preheat the oven to 190°C, gas mark 5. Place the sausages on a baking tray and cook for 20-25 minutes, turning halfway through the cooking time, until thoroughly cooked.
Cook your baked beans in a small nonstick pan on low-medium heat, for 3-4 minutes.
In a small bowl, beat eggs with salt. Using a nonstick pan or skillet, melt butter over medium-high heat until foamy. Pour in the eggs and stir until large, fluffy curds form and eggs are fully cooked through (typically after about 3 minutes).
Serve the scrambled eggs on buttered toast with a sprig of watercress and salt and pepper to taste.
In a small glass bowl, pour in the baked beans and sprinkle lightly with black pepper.
Finally, add the sausages to the plate.