Just think of the Harrison's as the flour to make the bread. Grind it finely in a food processor and use it as the base. Then add whatever you'd like into that base. The sky is the limit. If it's crumbly, then add water until it holds together, or any other liquid for that matter. Be creative! I've used green naked juice blends as the liquid in lieu of the water.
I dump all kinds of things into my bread: unsweetened coconut flakes, almond meal, flax meal, red palm oil, chia seeds, hemp seeds, broccoli, sweet potato, carrots, bell peppers, banana, zucchini...whatever you'd like to disguise and get into your birdie's bellies.