Toast bread in a 375F oven to golden. Melt butter in a small pan over medium heat until it foams. Stir in garlic 1-2 minutes then remove from heat and stir in parsley. Brush toasted bread liberally with garlic butter and reserve.
Heat EVOO in a large skillet over medium heat then add butter. When it foams, add onions and season with salt, pepper, thyme and bay. Cook until caramel in color, 30 minutes. Add consomm to onions.
Set rack in middle of oven and switch on broiler.
Heat griddle or cast-iron skillet over medium-high heat; drizzle with oil. Season room temperature steaks liberally with kosher salt and pepper. Cook 10 minutes, turning once. Let stand 5 minutes, thinly slice against the grain and drop into onion soup. Pile steak and onions onto toasted bread bottoms arranged on a baking sheet. Top with lots of cheese and melt under broiler. Set tops in place and serve.