Heat beef stock, garlic, and pepper flakes in a small sauce pot. Reduce to 2 C. Discard garlic for another use.

In a large mixing bowl, combine bread cubes, bell pepper, onions, and spinach. Add beef stock and a pinch of salt and pepper. Mix to combine.

Spread stuffing in an ungreased casserole dish. Cover. Bake at 375° for 20 minutes. Uncover. Bake an additional 20-25 minutes or until stuffing is no longer soggy.

Variations; Roasted bell peppers, jalapeños, paprika, shallots, jalapeños, balsamic vinegar, red wine vinegar, red wine, bacon, pancetta, prosciutto, caramelized onions, sherry, sherry vinegar, port, mushrooms, vegetable stock, chicken stock, rosemary, thyme, basil, parsely, cilantro, scallions, leeks, ramps, cayenne, fresno chile, poblano, celery seed, worchestershire, fennel, gruyere, arugula, asiago, asparagus, pearl onions, beer, bourbon, curry powder, sourdough, foccacia, challah, garlic bread, butter