1. Heat a wide, heavy casserole over high heat until very hot. Add a teaspoon of the canola oil, let it spread, then add the meat. Sear until deeply browned, 4 to 5 minutes per side. Transfer the meat to a large plate.
2. If the oil in the pan is very dark, wipe it out and add a teaspoon of fresh oil. Reduce the heat to medium, add the onions and cook, stirring occasionally, until softened, about 5 minutes.
3. Meanwhile, using a mortar and pestle, crush the garlic cloves into a paste along with the salt and pepper. Use a rubber spatula to spread this paste evenly all over the brisket.
4. When the onions are ready, pour in the boiling water, stirring to scrape up any cooked-on bits from the pan. Lay the brisket on top of the onions. Cover the pot and reduce the heat to low.
5. Simmer gently, covered, turning the meat over every 1/2 hour, for 1 hour. Stir the honey into the pan juices and continue to simmer covered, turning the meat every half hour, until it is thoroughly tender, 2 1/2 to 3 1/2 hours total (or up to 4 1/2 hours for grass-fed beef).
6. If serving immediately, transfer the meat to a carving board. Use a spoon to skim any fat from the surface of the pan juices. For a thicker gravy, simmer until the juices are thickened as desired. Slice the meat thinly against the grain and return it to the pot. Serve the meat with the onions and pan juices. (Alternately, let the meat cool in the pot, refrigerate it overnight, then skim off any solidified fat, gently reheat, covered, and proceed with slicing and reducing the pan juices).
Leftovers keep for a week in the fridge. Reheat gently or serve cold in sandwiches. The meat can also be frozen in its sauce, unsliced, for up to 2 months. Thaw overnight in the fridge. For baby, purée brisket with juices, cooked sweet potato, and steamed spinach.