Black Bean Burger with Mango, Purple Onion and Pea-Guacomole

4 BurgersPreparation time 3 hours (plus overnight soaking and chilling time)
350 g spelt flour (Typ 630)
10 g fresh yeast or ½ teaspoon dried yeast
1 tablespoons olive oil
100 g red onion, cut into extremely thin slices
6 tablespoons lemon juice
160 g black beans (or 360 g cooked black beans)
70 g long grain rice
40 g rice flakes
200 g frozen peas
1 avocado, peeled and pit removed
1 garlic clove, finely chopped
2 sprigs of mint, finely chopped
1 mango, cut into wafer-thin slices
1 bunch parsley, finely chopped
1 pinch ground cumin
8 Lollo Bionda lettuce leaves
1 patch of cress
A day in advance:
1. For the bread, knead spelt flour, yeast, 240 ml lukewarm water, 1 tablespoon olive oil and salt. Cover and let sit in refrigerator over night.
2. Mix purple onion with 5 tablespoons water, ½ teaspoon salt and 3 tablespoons lemon juice in a container and seal tightly. Let sit in refrigerator over night.
3. For the black bean patties soak black beans in cold water over night.
The Next Day:
4. Rinse black beans in a strainer and cook fully covered in water for 60 minutes. In a second pot, bring rice and water to a boil, cook fully covered in water for 10 minutes, then soak for another 20 minutes.
5. Preheat oven. Remove dough from fridge and form 4 burger buns. Lay buns onto a parchment lined baking tray and bake for 25 minutes.
6. For the Guacomole, boil peas in salted water for 3 minutes. Drain and rinse with cold water. Mix peas, garlic, avocado, 3 tablespoons of lemon juice, mint, salt and pepper. Purée mixture with a hand blender.
7. Drain black beans, rinse with cold water and drain well. Purée beans and rice. Mix in parsley, rice flakes, salt and cumin. Form mixture into 4 burger patties. Grill on each side for 3 minutes on a hot grill. Grill mango on each side for 1 minute.
8. Then, slice buns and spread with Guacomole. Stack burger, onions, lettuce leaves and grilled mango in buns. Serve sprinkled with cress.