Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness to ensure uniform cooking.
In a shallow bowl, combine the almond flour, smoked paprika, garlic powder, sea salt, and black pepper.
Press the chicken firmly into the almond flour mixture on both sides until it is thoroughly and evenly coated.
In a small ramekin, whisk together the Dijon mustard, raw honey, and apple cider vinegar until the glaze is smooth.
Heat the avocado oil in a non-stick skillet over medium heat and sear the chicken for 4 to 5 minutes per side until the crust is golden and crispy.
Lightly toast the sprouted grain bun in the skillet or a toaster until it is warm and slightly crisp.
Assemble the sandwich by placing the romaine lettuce and tomato slices on the bottom bun, followed by the crispy chicken.
Drizzle the honey-mustard glaze generously over the chicken and top with the remaining bun half before serving.