Bison Producers of Alberta :: 'Grinder' Meatball Sandwich

Ingredients

• 1 medium white onion, small dice
• 60 g butter
• 1.5 kg lean ground bison
• 120 g bread crumbs
• 3 large eggs
• 15 ml salt pinch each of black pepper and nutmeg
• 1 tsp. lemon zest
• 2 tbsp chili powder (ancho powder preferred)