Cut the broccoli into florets and pulse in a food processor until finely chopped (do not puree). Transfer the chopped broccoli to a large mixing bowl.

Heat a thin coat of oil in a skillet over medium-high heat. Add the fresh spinach and sauté just until wilted, 1–3 minutes. Transfer the spinach to the mixing bowl and, if it released excess liquid, press or squeeze out the liquid before adding.

In the bowl of a food processor or using a meat grinder, grind the cooked buckwheat together with the chicken breasts until combined and fairly uniform. Transfer this mixture to the large mixing bowl with the broccoli and spinach.

Finely dice or mince the onion and add it to the mixing bowl.

Add 1/4 cup plain bread crumbs (Panko), 1 large egg, and 1 Tbsp sour cream or mayo to the bowl. Season with salt and pepper to taste (we used 1/2 tsp salt and 1/4 tsp pepper). Mix thoroughly until the mixture holds together.

Form the mixture into oval patties using your hands.

Pour the 1 cup Italian bread crumbs into a shallow dish and coat each patty on both sides in the crumbs.

Heat a well-oiled skillet over medium heat (add enough oil to coat the pan). Place the coated patties in the skillet and cook, flipping 4–5 times, until the patties are golden on the outside and cooked through.

Remove the patties from the skillet and drain briefly on paper towels if desired. Serve warm.