If using fresh spinach, place it in a 10-inch quiche dish or pie plate. Cook in microwave, uncovered, at 100% for 5 minutes 30 seconds. Remove from the oven and let stand until cool.

Coarsely chop the spinach in a food processor, squeeze the excess moisture from the spinach. Transfer to a mixing bowl and reserve.

Finely chop the onion and garlic in the food processor. Add to the spinach. Add the bread crumbs, soy, pepper and ground beef and mix well.

Transfer the mixture to a 9 × 5 × 3-inch glass loaf pan, making sure there are no air pockets. Cook, uncovered, at 100% for 14 minutes.

Remove from the oven. Let stand, covered with a kitchen towel, for 10 minutes before serving.