Empty beans and lentils into a strainer, rinse and set aside.
Puree onion and garlic together (I use a bamix for this)
Heat the cooking oil in a sauté pan, add the onion and garlic, mushrooms and carrot and cook over medium heat for a few minutes until softened, then remove from heat.
Add all ingredients (including onion, garlic, mushrooms and carrot mix) to a large mixing bowl and use a potato masher to combine. Make sure all ingredients are well combined but try not to completely mash into a paste. leave a few chunks. If it's a little dry add a bit of water, if it's a little wet add more oats.
Preheat the oven to 180 degrees Celsius
With a spatula, transfer the mixture to a non-stick loaf tin. Work the mixture well into the pan so that it takes on the shape of the tin.
Garnish with sprigs of fresh Rosemary, then place it in the hot oven for about 40 min or until there is a light crust on top.
Turn the loaf upside down on a cutting board and give it a thump on the bottom to allow the loaf to come loose.
Slice in 2cm slices and serve hot with gravy and roast vegetables.