Work Week Lunch

0 Preheat your oven to 400 F. Grease a baking dish (I used a 9x9 one) with cooking spray.
1 Make the mashed potatoes: Add potatoes to a large pot and fill it with water just enough to cover the potatoes. Bring to a boil and add salt, and let the potatoes cook for 20 minutes, until they slide off a knife easily. (stick a knife in them to try it out when you think they're done). Drain the pot when they're soft enough, but leave the potatoes in there on a very low heat to evaporate more water for about 5-10 minutes. Then transfer to a bowl, mash the potatoes with butter and salt using a fork or masher to your desired consistency. (I also removed the skin when mashing - this is up to you) Cover your potatoes loosely and set aside.
2 While the potatoes cook: Add oil to a large pan over medium heat. After a minute, add the garlic and onions. Sautee for 5-7 minutes, stirring frequently, until they're fragrant and slightly darker in color. Add the lentils, broth, thyme, salt and pepper. Stir and bring to a boil, then turn the heat down and cook uncovered for 30 minutes, or until the lentils are tender. Add and stir in the frozen mixed veggies after the lentils have cooked for 20 minutes. Taste and adjust spices as it all cooks!
3 When it's done cooking, the mixture should be thick with only a little bit of liquid still in the pan. If there's too much, remove the pan from the heat and add the cornstarch. Whisk well until it's at your desired consistency. 
Pour the lentil veggie mixture in the greased baking dish and use a spoon or spatula to flatten the mixture out a bit. 
4 Carefully add the mashed potatoes on top. I used a regular spoon and added the potatoes by the spoonful because they're not easy to spread if you pour it on all at once! Once you have a layer of potatoes on top of the lentil mixture, you can use a spoon or fork to spread it more evenly. 
5 Place in the oven and cook for 15 minutes. Add a baking sheet under the dish just in case to catch any overflow. When it's done cooking, let it sit for 10-20 mins before slicing it!