Heat oil in a pan on a medium heat, then add onion, carrot, celery & garlic. Sweat for a couple of minutes, then add mushrooms and herbs. Cook the mushrooms until slightly golden in colour.
Add tomato paste. Stir through well, then add the brown rice flour and mix to coat.
Add red wine and let cook for a couple of minutes. Add aminos, vegan Worcestershire, marmite, bay leaf, and stock. Stir through well. Bring to a gentle simmer.
Drain & rinse the lentils (if using canned), then add to pan. Season to taste with salt and black pepper, stir to combine, then simmer on low-medium heat for 30-40 minutes.
Prep the bean-mash: Add quartered potatoes to a pan of boiling, lightly salted water. Boil for 15 minutes or until tender, then drain. Drain & rinse a can of butter beans, then add them to the potatoes. Drizzle in olive oil, milk, and add the mustard. Remove from heat. Season with salt and black pepper, then mash the potatoes until smooth and creamy.
Serve the Butter Bean Mash with the Lentil Bourguignon over the top and garnish with fresh parsley or thyme – enjoy!