Make the dressing: In a large mixing bowl, whisk together the lemon juice, garlic, olive oil, Aleppo pepper, and a pinch of salt.
Step 2
Mix: To the bowl with the dressing, add the cannellini beans, cherry tomatoes, red onion, parsley, and olives. Stir to coat with dressing, then gently fold in the tuna and basil, being careful not to break up the tuna too much. Taste for seasoning and add more salt, Aleppo pepper, and lemon juice if desired.
Step 3
Finish and serve: Divide the spinach among four plates and top with the tuna salad. Serve immediately or refrigerate for up to 2 hours.