In a medium pot of water or a rice cooker, cook 1/2 cup of dry quinoa with 1 cup of water until the liquid has absorbed. Let cool. This can be done up to 2 days in advance.
In another medium pot of water, cook 1/2 cup dry brown lentils with 2 cups of water until the liquid has fully absorbed. Let cool. This can also be done up to 2 days in advance.
Meanwhile, bake the bacon on a large sheet pan in a 400 F oven for 25 minutes until crispy, or fry in a pan until crispy. Drain fat in a bowl/leftover can and set aside to cool before crumbling.
In a large bowl, combine the sour cream, white wine vinegar, mayonnaise, maple syrup, garlic, salt, and black pepper and whisk until smooth. Set aside.
In another large bowl, combine the broccoli, carrots, bacon, lentils, quinoa, walnuts, dried cranberries, feta cheese, sunflower seeds, pumpkin seeds, and red onion. Toss the salad to combine.
Pour the dressing over the salad and stir until everything is evenly coated.
The salad can be served immediately. For best flavor, cover the bowl and chill for 1-2 hours to let the flavors mingle before serving.
Notes
The salad tossed in dressing can be stored in an airtight container in the refrigerator for 3-4 days. For meal prepping further in advance, the dressing and salad can be stored separately and tossed together before serving.