Fish finger sandwich

Name: Fish finger sandwich
Yield: Serves 4
Ingredients: 10 g garlic powder; 10 g onion powder; 20 g nutritional yeast flakes; 2 medium eggs; 4 large sole fillets; 40 g pumpkin seeds; 40 g fine rolled oats; 150 g panko breadcrumbs; 200 g celeriac, peeled and grated; 10 g wakame powder; fine salt; fish fingers; 3 bulbs of garlic; 200 g mayonnaise; 200 g butternut squash, peeled and grated; vegetable oil for shallow frying; salt and freshly ground black pepper; 50 g plain flour; 4 brioche buns, split in half and toasted; salt and freshly ground black pepper