Heat on the stove a combination of olive oil and butter. If you feel strongly about using one or the other, but not both, fine. Once it is all hot and yummy, add lots of white pepper, minced garlic, and minced onion, and a little sage, celery salt, and oregano.
Toss the bread cubes in the fat until almost saturated.
Toast in a 350 degree oven for a little while; stir regularly.
Then when you have a bit of room to be able to supervisor the croutons, broil them. But only under TOTAL supervision. This should just take a minute. Then pull out, and let cool a couple minutes before noshing.