Thinly slice the onion. Deseed and thinly slice the pepper.
Heat the oil in a large frying pan and gently cook the onion and pepper for 10-15 minutes until soft. Turn off the heat and mix in the chutney.
Preheat the oven to 200ºC.
Unroll the pastry onto a chopping board (keep the packaging sheet underneath) then cut into 10/12 rectangles or 15 squares. Transfer these to a large, lined baking sheet (you might need 2 trays).
Spread the onion and pepper mixture over the tarts. Cut the chorizo slices and arrange these on top (2/ larger tart, 1/small tartlet) . Scatter the pine nuts ( and the cheese, if used) on top.
Bake for 15-20 minutes until golden brown and cooked through.
Serve with a salad as a meal, or scatter some fresh herbs, watercress or rocket over them.