Preheat oven to 400°F. Chop all vegetables and prepare ingredients. Slice the carrots in half lengthwise, or quarters if they are thicker, then slice them thin.
In a large skillet (you can use an oven safe skillet that can also bake the casserole, or transfer the filling to a baking dish later) over medium heat, begin to brown the beef, breaking it up with a wooden spoon.
After a couple minutes, move the browning beef to one side of the skillet and add the onion, carrot, and zucchini to the other side. Use the fat from the beef to saute the vegetables. Season with salt and pepper.
Stir occasionally, breaking up the beef. Keep the beef and veggies to separate sides of the skillet as best you can, about 12 minutes.
When the beef is fully cooked and the veggies softened, add the flour, green beans, fresh herbs and greens, and garlic. Stir everything well and cook another minute.
Add the Worcestershire sauce, beef stock and milk. Reduce the heat to medium low and bring the liquid to a simmer to thicken, about 15 minutes. Whisk often to thicken the filling.
When the liquid has thickened, turn the burner off. You can transfer the filling to a casserole dish, or bake it right in the skillet if it is oven safe. Sprinkle the top evenly with cheese. Add the frozen tater tots in an even layer over the top, squeeze in as many as you can!
Bake at 400℉ for about 30 to 40 minutes or until the tots are browned and crispy and the filling is hot and bubbly. You can broil the top a few minutes if you want the tots crispier. If your baking dish is very full, put a sheet pan under it in the oven to catch any drips.
Let sit on the stovetop 5 or 10 minutes before serving. Garnish with fresh chopped chives or thyme.