Cut the onion into thin slices and fry it gently in a pan with the vegetable spread or olive oil.
Add the vegetables cut into small cubes, salt, pepper, sage and rosemary leaves to taste, cover with a lid and simmer on low heat for 10 minutes.
Combine the flour with thyme leaves, salt and cold margarine cut into cubes. Mix quickly with a fork to get a crumbly dough. Add in the sunflower seeds, mix briefly and allow the crumble to cool in the fridge.
Grease lightly an 8 inch baking pan (or four small pots), pour the vegetables into it and top with the crumble. Bake at 360°F for 30 minutes (20 minutes for the single pots).