Preheat oven to 375 degrees and lightly butter a 9 x 13 baking dish or large casserole. In a large bowl combine the half and half, eggs, salt, orange zest, thyme, and maple syrup and whisk to combine thoroughly. Add the bread cubes (be sure not to use more than 10 cups or the strata will be too dry) and toss to combine. Next, add the ham (tearing into smaller pieces if necessary), the pears, and about half of the cheese. Toss once again to evenly distribute the ingredients. Transfer the mixture and all of its liquid to the prepared baking dish and sprinkle with the remaining cheese (at this point the strata may be covered and refrigerated overnight). Bake the strata for 45-50 minutes, or until nicely browned and very hot in the middle. If baking the strata directly from the refrigerator, add 15-20 minutes to its cooking time, covering it loosely with foil for the additional time to prevent over-browning.