Healthy pesto spread and sandwich

Ingredients

• 1/2 cup frozen chopped spinach
• 2 garlic cloves
• 1/2 cup fresh basil
• 1/4 cup walnuts, roughly chopped
• 2 tbsp grated parmesan cheese
• 3 tbsp olive oil
• 2 slices whole wheat bread
• 2 slices reduced-fat provolone cheese
• 2 slices tomato
• 2 to lettuce leaves