Vegetarian Stroganoff (Lentil & Mushroom)

Ingredients

• 1.5-2 tablespoons olive oil
• 1 large onion (halved and sliced into half moons)
• 1 teaspoon salt
• 1 lb cremini button mushrooms (sliced, 500 grams)
• 1 tablespoon olive oil
• ½ teaspoon salt
• 2 tablespoons butter
• 2 teaspoon Dijon mustard
• 2 cloves garlic
• ½ teaspoon ground black pepper
• 1.5 cups vegetable stock
• 1.5 tablespoons flour (gluten-free or regular)
• 2 tablespoons water (or stock for slurry)
• 3 cups cooked brown lentils (canned or cooked at home, strained)
• ⅔ cup sour cream (light can be used)
• Parsley for garnish
• Extra salt to taste