For the honey mustard sausages:
In a small bowl, mix together the honey and Dijon mustard with 2 Tbsp (30 ml) warm water. Set aside. Heat a large frying pan over medium-high heat and add the olive oil. Fry the sausages for 8–10 minutes, turning regularly, until just golden. Pour the honey-mustard mixture into the pan and cook for 3–4 minutes, turning the sausages and brushing until sticky and well glazed.
For the scrambled eggs:
Whisk the eggs and milk together. Heat a separate frying pan over medium-low heat and add a little olive oil. Pour in the egg mixture and gently stir with a silicone spatula, scraping the base of the pan, until softly scrambled. Stir in the butter and season to taste.
To serve:
Slice the croissants open and add a fan of avocado slices to the bases, then top with scrambled eggs. Halve the sausages lengthways and add on top of the eggs. Finish with pickled red onion and serve immediately.