1/ Preheat the oven to 180℃ Deseed the pepper and cut it into thick slices. Slice the onion. Finely slice the garlic. Roughly chop the spinach leaves.
2/ Put all the ingredients except the spinach and olive oil in a shallow casserole or oven proof skillet. Drizzle the olive oil over the top and mix to all together. Put in the oven for 35 mins.
3/ Remove from the oven and mix through the spinach leaves.