In a 12-inch skillet over medium-high heat, cook the pancetta in the olive oil, stirring frequently, until the pancetta has rendered much of its fat and is nicely browned, 4 to 5 minutes. Increase heat to medium-high, stir in the carrot, shallot, and red pepper flakes and cook to soften the vegetables, 1 to 2 minutes. Add the sprouts, season lightly with salt and pepper, stir to coat with the fat, and cook, stirring, until the sprouts wilt slightly and a few brown lightly, 2 to 3 minutes.
Add the broth and thyme, cover with the lid slightly ajar, and adjust the heat to a lively simmer. Cook the sprouts until they're just barely tender, 4 to 6 minutes. Remove the lid, increase the heat to medium-high and cook, stirring frequently, until all the liquid has evaporated and the sprouts are quite tender (but not mushy), about 3 minutes. Off the heat, gently stir in the sun-dried tomato, butter and lemon zest. Season to taste with salt and pepper.
Notes
If you are preparing this recipe as GLUTEN FREE, just make sure that your pancetta is free of gluten, and that you are using a brand of broth that is known to be GF.