Snipped the sun dried tomatoes and roasted red peppers into very thin slivers with your kitchen scissors
Using the marmite / yeast extract and a pint / 500ml boiling water, make a jug of stock
Make a roux with the oil and flour. Add the hot stock in about 4 goes.
Between each addition of stock stir the mixture until all the liquid incorporates into the flour and oil. (If you lift the pan off the heat and beat hard with a wooden spoon after the liquid is incorporated your sauce will be beautifully glossy).
By the time all the liquid is added you should have a sauce which will coat the back of a spoon. If not add more stock. Stir in the mustard, oregano, garlic, red peppers and sundried tomatoes in slivers.