Prepare the chive oil by blitzing the chives, salt, and 200ml (6.8 fl oz) sunflower oil with a hand-held blender until smooth. For best results, prepare this the night before to allow the flavour to infuse.
To make the smoky beans, heat 3 tbsp (45 ml) of oil in a large, heavy-based pan over a medium-low heat. Gently sauté the onion until softened.
Add the tomatoes, salt, sugar, cayenne, tomato purée, white wine, and bay leaf.
Stir in 100ml (3.4 fl oz) of water, cover, and bring to a simmer over a medium heat.
Cook for 15 minutes until the tomatoes are soft.
Remove the pan from the heat, discard the bay leaf, and blend the sauce with a hand-held blender. For an extra smooth texture, pass the sauce through a sieve into a clean pan.
Return the sauce to a low heat and cook for about 20 minutes, stirring occasionally, until it has reduced and thickened.
Stir the drained haricot beans and the smoke oil into the tomato sauce.
Taste and adjust seasoning if necessary.
Keep warm over a very low heat.
To poach the eggs, bring a large, deep saucepan of water to a boil with 4 tbsp (60 ml) salt and the vinegar.
Once boiling, reduce the heat to a low simmer.
Crack two eggs into separate small bowls. Create a gentle vortex in the water with a spoon and carefully drop the eggs, one at a time, into the centre.
Cook for 3-5 minutes, until the whites are set but the yolks are runny.
Remove with a slotted spoon to a bowl of cold water.
Repeat with the remaining eggs.
When ready to serve, briefly return all poached eggs to the hot water for 1 minute to warm through.
Divide the smoky beans over the 4 slices of buttered toast.
Top each with 2 well-drained poached eggs and a sprinkle of sea salt.
Garnish with a large handful of watercress, a generous drizzle of chive oil, and a few extra chopped chives.