Place oil and chopped veggies and garlic in, stir. Add the water and lentils. Place lid on and let cook on high for about 3 hours until lentils are soft.
After lentils are cooked stir in Vegetable broth powder and diced tomatoes, turn slow cooker to low and let warm until time to eat. Just before serving add 1-2 Tablespoons, or to taste, of Balsamic vinegar. Can optionally mash some of the lentils with a potato masher or blend with a hand blender for a thicker consistency or just eat it like it is.
Add salt and pepper to taste!
Notes
Want to make this in the Instant Pot? Just cook the first seven ingredients on High Pressure for 10 minutes. After depressurizing, stir in the tomatoes and balsamic vinegar. Add salt and pepper to taste.No salt added vegetable broth can be substituted for the water and homemade vegetable powder.