In a medium sauté pan, heat 2 tsp. olive oil over medium heat. Add garlic and stir until fragrant, 10-15 seconds. Add white beans and toss until lightly browned, 2-3 minutes. Set aside to cool. Combine cooled bean/garlic mixture in the bowl of a food processor with lemon juice, tahini, celery salt and black pepper. Spin until mostly smooth. Drizzle olive oil in as the food processor runs, being careful not to overfill it. The hummus should be very smooth and homogenous. Pour hummus into a bowl and stir in feta and giardiniera by hand. Refrigerate until ready to serve. Serve with toasted slices of Pane Turano.