Take the sardines out of the can and break into chunks. Keep aside
Mix the tomato puree and pepper flakes in a small bowl with 2 tablespoons water to form a paste.
Heat the oil in a pan, then pour in the onions.
Fry the onions until translucent.
Add garlic, curry powder and ginger.
Allow to cook for about 30 secs before adding the tomato puree and pepper paste.
Add the stock and the sardine chunks.
Add some salt to taste, cover the pan and allow to simmer for about 15 mins.
Remove from heat and stir in the chopped spinach.
Allow to cool.
While the sauce is cooling, add some water to the garri to make it moist. Add enough water to make it slightly damp, not soggy.
Pour the sauce into the moist garri and mix thoroughly.
Serve with the chopped tomatoes.