White Bean Avocado Sandwich

Name: White Bean Avocado Sandwich
Prep time: 10 min
Cook time: 5 min
Total time: 15 min
Cuisine: American
Ingredients: 1 large avocado (cut into about 1-inch pieces); 15 ounces white beans (canned, drained and rinsed); ¼ cup diced red onion; 1 tablespoon avocado oil (or olive oil); 1 teaspoon sriracha (or to taste); 1 tablespoon nutritional yeast ((optional)); 1 small garlic clove (or ½ teaspoon garlic powder); 1 lime (juice and zest); Salt & freshly ground black pepper (to taste); 1 cup leafy greens; 4 to 6 slices bread; 1 small cucumber (thinly sliced (optional))