Rinse the fresh baby spinach under cold running water and pat dry.

Hull the strawberries, slice them into quarters or thin slices.

Slice the red onion thinly if using.

Toast the sliced almonds in a skillet over medium heat for 5-7 minutes, stirring frequently.

Whisk together balsamic vinegar, Dijon mustard, honey, olive oil, salt, and pepper in a small bowl for the dressing.

In a large mixing bowl, combine spinach, sliced strawberries, and red onion and toss gently.

Sprinkle toasted almonds and optional feta cheese over the salad mixture.

Drizzle the dressing over the salad, toss gently, and serve immediately.