Hawaiian Style Crispy Pork Belly Loco Moco

1 pound pork belly
Garlic salt
Black pepper
1 Tbsp reserved pork belly oil
1 Tbsp grape seed oil
1 small onion, sliced
2 Tbsp butter
8 oz white button mushrooms, sliced
5 garlic cloves, minced
1/4 tsp dried thyme or 3/4-1 tsp fresh thyme
1/4-1/2 tsp black pepper
2-3 Tbsp flour
2 cups warm/hot beef broth
1/2 Tbsp Better Than Bouillon Beef
1 Tbsp soy sauce
1 tsp worcestershire sauce
2 eggs, any style
2 scallions
Fried onions