1. Preheat oven to 350°F. Chop onion and prep garlic. 
2. Add oil to a large skillet and heat over medium-high heat until glistening. Add chopped onion and cook, stirring frequently for about 3 minutes or until they start to soften and become translucent. Add the ground beef, breaking into pieces and cook until browned (about 6-8 minutes). Drain excess grease from the skillet. 
3. Lower the heat to medium low and add the broth, vegetables, tomato paste, flour, garlic and seasonings. Stir until fully combined and flour has dissolved into the mixture. 
4. Transfer to a 9x9 inch square baking pan that is lightly sprayed with oil or a 9 inch pie dish. Press the mixture into the pan so it is evenly spread out. Line the tater tots over top to cover completely. You may need more or less than recipe suggests based on how close you line them and the size or shape of your pan. 
5. Bake for about 45-50 minutes or until the tops of the tater tots are golden brown and crispy. For extra crispy tater tots, broil on high for the last 2-3 minutes. 
6. Remove from oven and allow to cool for about 5 minutes before serving.

Notes 

• Ground beef buying tip: Be sure to select ground beef with a bright, red color that is firm to the touch and doesn’t have excessive liquid in the package. Store ground beef in your refrigerator for 1-2 days, or in the freezer for up to 4 months. 
• Use frozen tater tots. If you don't use frozen tater tots in this recipe, the tots will not bake up as crispy. It is a definite MUST if you like your tater tots golden and crispy. 
• While cheese is not an ingredient in classic shepherd's pie, it's great on top! My husband preferred shredded cheddar cheese over top of his tater tots after this came out of the oven. It is definitely a delicious addition. You could also stir some into the beef mixture if desired or add on top of the tots in the last 5 minutes of baking.