Sweet Potatoes & Chickpeas with Peanut Butter Sauce

INGREDIENTS

1 dry onion, thinly sliced
2 cloves garlic, grated
2 tbsp tomato paste
1 tsp ginger powder
1 tsp cumin
1 tsp dry coriander
½ tsp all spice or ½ tsp cinnamon & ¼ tsp nutmeg
1 medium sweet potato, cut into medium cubes
250 g boiled chickpeas (about 150 g. dry)
500 ml vegetable stock or water, hot
500 g grated tomatoes
125 g Peanut Butter
400 g Swiss chard or spinach, roughly chopped
Olive oil
Salt & freshly ground pepper