Melt the margarine in a sauce pan under moderate heat.
Add the onions , carrots until browned lightly.
Mix in the flour and cook to a sandy mixture.
Remove from heat and mix in the puree.
Return to the heat and gradually add in the stock(hot).
Stir until it boils, add the garni and season lightly.
Simmer for about an hour and skim when needed.
Remove the garni: pass through a sieve then through a strainer.
Return to a clean pan, add the seasoning.
Bring to boil.
Serve with fried or toasted croutons separately.