Baby Spinach Salad with Dates and Almonds

Name: Baby Spinach Salad with Dates and Almonds
Prep time: 15 min
Cook time: 5 min
Total time: 20 min
Cuisine: Middle Eastern
Ingredients: 1 tbsp white wine vinegar; 1 small red onion, thinly sliced; 7-8 pitted Medjool dates, sliced lengthwise; 2 tbsp unsalted butter; 2 tbsp olive oil; 2 whole wheat pitas, torn into small pieces; ½ cup whole unsalted almonds, chopped; 2 tsp sumac, optional; ¾ tsp chile flakes; 5 oz baby spinach leaves; 2 tbsp freshly squeezed lemon juice; salt