Salmon Burgers with Caper Aioli

Ingredients

• 3/4 pounds skinless, boneless salmon
• 1 tsp Dijon mustard
• 1 shallot
• 1/4 cup coarse bread crumbs (GF if desired)
• 1/2 tbsp capers, drained
• Salt and black pepper
• 1 tbsp butter or olive oil
• 1 heirloom tomato, sliced
• 1/2 small red onion, sliced rings
• 4 lettuce leaves, such as butter, romaine, or use a handful of spinach
• 2 brioche buns (or other soft buns)
• 1 lemon
• Your favorite aioli spread or DIY