In a bowl or jar, whisk together all of the ingredients for the poppy seed dressing. Taste for seasoning then cover with a lid and refrigerate until ready to use.
Arrange the spinach onto a serving platter or add it to a serving bowl. Top the spinach with the sliced strawberries and avocado, crumbled goat cheese, and sliced almonds.
Just before serving drizzle the salad with the poppy seed dressing. You can also serve the dressing on the side.
Notes
To prevent the avocado from browning as quickly, toss the avocado slices in fresh lemon juice.