Place avocado flesh in a medium size bowl with the chilli flakes and lemon juice. Mash roughly with a fork, season to taste with sea salt and freshly ground black pepper.
Toast muffins until golden. Divide spinach leaves evenly over half the toasted muffins. Top with the mashed avocado and some sliced smoked salmon. Serve with remaining muffin half and a wedge of lemon.
Try adding a poached or fried egg on top.
Serving Size 4