Best Tater Tot Casserole

Ingredients

• 1 bag (32 ounce size) frozen tater tots
• 1 pound ground beef, browned
• ½ teaspoon salt, or to taste
• ¼ teaspoon black pepper, or to taste
• 2 cans (14.5 ounce size) green beans, drained
• 1 bag (16 ounce size) frozen mixed vegetables
• 1 can (10.75 ounce size) cream of mushroom soup
• 1 tablespoon dried onion
• ¼ cup milk
• 1 cup shredded cheddar cheese