Drain the canned salmon and place it in a medium mixing bowl, flaking it thoroughly with a fork to break up any large chunks.
Add the egg, almond flour, minced red onion, chopped fresh dill, lemon zest, lemon juice, sea salt, and black pepper to the bowl.
Mix the ingredients together until well combined, then form the mixture into two even, firm patties.
Heat the olive oil in a non-stick skillet over medium heat until shimmering.
Carefully place the patties in the skillet and cook for 4-5 minutes per side until they are golden brown and crisp.
While the patties cook, mash the avocado in a small bowl with a tiny pinch of salt until smooth.
Serve the warm salmon patties over a fresh bed of baby arugula and top with the creamy avocado mash.