To a medium pot or a dutch oven, heat olive oil over medium heat. Once hot, add onion, carrot, celery, and mushrooms and saute for 5-6 minutes, until fragrant. Add minced garlic and cook for 2 minutes.
Then, add flour (or chickpea flour) and stir. Cook for 2 minutes, stirring frequently to prevent burning. Add vegetable broth, coconut milk, potatoes, salt, black pepper, thyme, rosemary, and oregano. Stir. Bring to a boil and simmer over medium-low heat for 10 minutes.
Next, add lentils and frozen peas and cook for 5 more minutes, stirring frequently. If the mixture tends to burn easily, add a splash or two of water or broth. Remove from the heat.