A good steak tartare is the pinnacle of treat-yourself eating: velvety bits of bovine blend with tart and umami flavors to prime the palate at the outset of a meal, while nuanced texture and taste encourage you to savor each bite. The best place to experience such luxury in Denver is at Acorn, the wood-fired restaurant tucked into the Source. Chef Steven Redzikowski's kitchen starts its tartare with a major upgrade to the meat: wagyu beef, which has a softer texture and better marbling than the tenderloin that usually forms the basis of this dish. From there, the kitchen adds lemon for acidity and honey mustard for zip, and tops the raw steak with verdant celery, spicy radish, a generous dusting of pungent Pecorino-Romano cheese and, crucially, a hefty sprinkle of black pepper, which really makes it pop. Paired with cracker-crisp slices of garlic-and-poppyseed-forward everything lavash, this is a dish you'll want to eat with a tiny fork while sipping a glass of expensive bubbles. The bubbles, at least, can be accommodated.