Grab a large mixing bowl and add your 4 cups fresh spinach leaves—don't pack them down, just let them sit loose and fluffy. Rinse them first if you bought them loose, or if they're pre-washed, you're golden. You want them fresh and crisp when you start building your strawberry spinach salad summer, so do this step right before serving.
Slice your strawberries into thin, even pieces (about 1/4-inch thick works perfectly). I personally slice mine lengthwise so they look prettier on the plate, but honestly any way works. Add them to the spinach bowl gently so you don't bruise them.
Toss in your 1/4 cup crumbled feta cheese and 1/4 cup sliced almonds, plus the 1/4 cup thinly sliced red onion. Mix everything together with your hands or two forks until it's evenly distributed. Don't panic if it looks kinda crowded in the bowl right now—the dressing will tie everything together.
In a small separate bowl, whisk together 2 tablespoons apple cider vinegar, 2 tablespoons olive oil, 1 tablespoon honey, and 1 teaspoon lemon juice. Whisk until the honey dissolves completely—this usually takes about 30 seconds of solid whisking. Add your 1/2 teaspoon salt and 1/4 teaspoon black pepper, then taste and adjust as you go.
Pour the dressing over your salad greens right before serving (this is important so the spinach doesn't get soggy). Toss everything together gently using two forks or salad tongs until every leaf gets coated with that poppy seed dressing-style vinaigrette. Don't go crazy—you want the greens to stay perky, not get all wilted and sad.
Top with your 2 tablespoons toasted pumpkin seeds right before plating. These add a nutty crunch that makes your strawberry spinach salad summer feel fancy without any extra effort. I always do this last because they stay crunchier if they're not sitting in the dressing.
Plate immediately and serve while everything's still crisp and fresh. If you're serving at a party, you can prep all the components separately and let guests assemble their own bowls. This way everyone gets maximum crunch and flavor in every bite.