Cut 5 thick-cut bacon slices crosswise into ½-inch pieces. Place in a large skillet and cook over medium-low heat until browned and crisp, 8 to 10 minutes. Meanwhile, prepare the following, adding each to the same large bowl as you complete it: Cut 1 pound broccoli florets into coarse ¾-inch pieces (about 6 cups). Finely chop ½ medium red onion (about ⅔ cup). Grate 3 ounces sharp or medium cheddar cheese on the large holes of a box grater if needed (about ¾ cup).
When the bacon is ready, transfer it with a slotted spoon to a paper towel-lined plate. Transfer 2 tablespoons of the rendered bacon fat to a medium bowl and discard the remaining fat. Reserve the skillet (no need to clean it).
Add ½ cup mayonnaise, ½ cup plain Greek yogurt, 3 tablespoons vinegar of choice, 2 tablespoons honey or granulated sugar, 1 teaspoon kosher salt, and ½ teaspoon black pepper to the bacon fat and whisk to combine.
Heat the reserved skillet over medium heat. Add ½ cup raw sunflower seeds and spread into an even layer. Cook, stirring occasionally, until lightly toasted and fragrant, 1 to 2 minutes. Add the sunflower seeds, dressing, half of the cooked bacon, and ⅓ cup dried cranberries to the broccoli mixture. Toss until well-combined. Garnish with remaining bacon and serve chilled or at room temperature.
