1 medium onion, thinly sliced
1 garlic clove, crushed
2 medium tomatoes, chopped
2 green chilies, minced
1 teaspoon tamarind powder or paste (salt free) or dried tamarind pods if available, optional*
1 tablespoon ground cumin
1 tablespoon coriander
12 ounces spinach, chopped (frozen or fresh)
2 cups cooked chickpeas or 1 (15 ounce) can no-salt-added or low-sodium chickpeas, drained
1/4 teaspoon cayenne pepper, or to taste