Preheat your oven to 375°F and line a small baking sheet with parchment paper or foil.
In a small skillet, warm 1 teaspoon of olive oil over medium heat. Add 2 tablespoons finely chopped onion and cook until soft and lightly golden, about 3–4 minutes. Stir in 1 small minced garlic clove and cook for another 30 seconds. Remove from heat and let it cool slightly.
In a medium bowl, combine ½ pound ground beef, the sautéed onion and garlic, 1 tablespoon ketchup, ¼ teaspoon Worcestershire sauce, ½ teaspoon salt, 2 tablespoons breadcrumbs or crushed crackers, and 1 egg. Gently mix just until everything comes together — don’t overwork it or the meatloaves will be dense.
Form the mixture into two small loaves and place them on one side of your prepared baking sheet. Brush the tops with a little extra ketchup.
On the other side of the pan, toss ½ pound trimmed green beans with 1 teaspoon olive oil, a pinch of salt, and black pepper. Spread them out in a single layer.
Roast everything together for 20–25 minutes, until the meatloaves are cooked through (160°F internally) and the green beans are lightly caramelized and tender-crisp.
While the meatloaves and green beans roast, place 1 large peeled and cubed russet potato in a pot of salted water. Bring to a boil and cook until fork-tender, about 10–12 minutes. Drain, then mash with 2 tablespoons butter, ½ cup milk, and a pinch of salt and pepper until smooth and creamy.
Plate the mini meatloaves with the roasted green beans and a scoop of mashed potatoes for a simple, satisfying dinner made just for two.