Grill the venison sausages under a medium grill, or use a George Forman grill. Once cooked lay aside to cool whilst you prepare the rest of the ingredients.
Spray the bottom of a stove proof casserole dish or a medium sized saucepan with the cooking spray. Turn the heat on high and when the oil starts to bubble reduce the heat to medium.
Add the onion and sauté for 3 to 4 minutes until soft, stirring to avoid sticking to the pan.
Once the onion is softened add the peppers and mushrooms and saute for a further 3 to 4 minutes.
Stir in the tomato puree, mixed herbs, cornflour mixture, stock and dijon mustard and combine everything well.
Add the tin of tomatoes and stir together.
Bring the contents of the pan to the boil, then turn down to simmer.
Whilst simmering away cut the sausages into half lengthways and then half the halves, and cut those in half so that you have 8 pieces from each sausage.
Add the sausage pieces to the saucepan and cook for 2 to 3 minutes until everything has cooked through and season with salt and pepper.
Divide between bowls and serve with couscous or basmati rice.