In a large bowl, combine the tuna, celery, bell pepper, onion, dill or parsley, mustard, almond flour, salt and pepper. Using clean hands, mix until combined.
In a separate bowl, whisk the eggs until well combined and slightly frothy. Pour the eggs into the bowl and mix until well combined and it begins to clump. If you notice that your mixture is too dry and flakey, whisk an additional egg and add one or two tablespoons at a time until it begins to clump up. If your mixture is too wet, add one or two tablespoons of almond flour.
Using a 1/3 cup measuring cup, portion out equal-sized mounds. Form the mounds into rounds and then carefully flatten into cakes.
Preheat a non-stick skillet over medium to medium-high heat. Add olive oil and heat until shimmering. Working in batches so as not to overcrowd the pan, carefully lay in the tuna cakes and cook, undisturbed, until golden brown, three minutes. Flip and cook until golden brown on the second side, three minutes. Transfer the cooked cakes to a tray lined with paper towel to absorb excess oils.
Serve immediately with lemon wedges.