Lentil Burgers with Roasted Red Pepper Sauce

1 large egg                        
2 tbsp gluten-free flour
1 ½ tbsp tahini or nut butter            
1 ½ tsp red or white wine vinegar
1 ½ cups cooked lentils        
½ cup grated sweet potato
5 oz. frozen spinach, thawed and squeezed dry    
¼ cup chopped sun-dried tomatoes
¼ cup chopped nuts, optional            
2 oz. crumbled feta cheese, optional (make sure it is sheep or goat milk only)
2 tbsp finely diced onion                
1 tbsp chopped fresh parsley or cilantro
1 clove garlic, minced                 
½ tsp Celtic sea salt

Preheat oven to 400°F. Line baking sheet with parchment paper. Combine egg, flour, tahini, and vinegar in bowl. Stir in remaining ingredients, then mash together until mixture is firm enough to shape into cakes. Shape mixture into 1/4-cup patties with wet hands. Bake on prepared baking sheet 25 minutes, turning once, or until cakes are browned.  Serve with red pepper dipping sauce (below).

Red pepper sauce
1 ½ cups roasted red peppers, drained       
 ½ cup toasted almonds
1 clove garlic                        
2 tsp red wine vinegar

Purée all ingredients in food processor.