Prepare the dressing by combining balsamic vinegar, olive oil, minced garlic, Dijon mustard, strawberry jam, salt, and pepper in a jar or bowl. Mix well and adjust seasoning if needed.
Toast raw almonds over medium heat for 2-5 minutes until golden brown. Let cool.
In a large bowl, layer spinach, strawberries, avocado slices, red onion, feta cheese (or alternative), toasted almonds, and pistachios.
Drizzle with dressing just before serving or offer on the side for customization.