2 Tbsp. extra-virgin olive oil

1 large yellow onion, finely chopped

4 cloves garlic, coarsely chopped
Kosher salt
1 1/2 lb. (85% lean) ground beef
1/4 cup #1 fine bulgur wheat

1/2 cup boiling water
Freshly ground black pepper
2 Tbsp. unsalted butter
1 Tbsp. all-purpose flour
3/4 cup low-sodium chicken broth
1 (10.5-oz.) can cream of mushroom soup
1/2 cup frozen corn kernels
1/2 cup frozen green beans
1 Tbsp. Worcestershire sauce
1 tsp. yellow mustard (optional)
6 oz. extra-sharp yellow cheddar, grated, divided
    1. Directions
        1. Combine bulgur and boiling water in a heat proof bowl. Cover and let sit for 15 minutes.
        2. Preheat oven to 375°. In a large skillet over medium-high heat, heat oil. Add onion and garlic and cook, stirring constantly, until lightly browned, 7 to 8 minutes; season with salt.
        3. Add beef, breaking up meat into smaller pieces. Cook, stirring frequently, until browned and no longer pink, 6 to 7 minutes; season with salt and pepper. Combine with cooked bulgur, discarding any remaining water. Transfer to a medium bowl.
        4. Reduce heat to medium and melt butter. Add flour and cook, whisking constantly, until roux is bubbly and fragrant, 1 to 2 minutes. Slowly add broth, then whisk constantly until mixture simmers and thickens; there should be no lumps. Stir in soup.
        5. Add meat mixture, corn, beans, Worcestershire, mustard (if using), and half of cheese; season with salt. Pour mixture into a 13″ x 9″ baking dish. Top with remaining cheese. Arrange tater tots in horizontal rows on top, leaving a small gap between each.
        6. Bake casserole until center and edges are bubbling, 35 to 40 minutes. Top with scallions.