Prepare the sauce: In a bowl, add mayonnaise, tomato ketchup, hot sauce, onion powder, red chilli powder, garlic powder, and Himalayan pink salt. Whisk well and transfer to a squeeze bottle.
Make scrambled eggs: In another bowl, whisk eggs, milk, and a pinch of Himalayan pink salt. In a frying pan, melt butter over low heat, add the whisked eggs and cook gently until scrambled. Set aside.
Prepare croissants: Cut croissants in half. Grease a frying pan with cooking oil and toast croissants until golden brown.
Assemble the croissants: On the toasted croissant halves, spread the prepared sauce, then layer lettuce leaves, tomato slices, cheddar cheese slices, mortadella slices, and scrambled eggs. Cover with the other croissant half to make a sandwich. Makes 2 sandwiches.