Preheat oven to 275ºF.
Season beef with salt and pepper on both sides and dredge with flour.
Heat a large skillet with 1 tablespoon EVOO and 1 tablespoon butter over medium-high heat. Brown half the meat on each side and remove to a plate. Add more oil and butter and repeat. Once all the meat is browned, add remaining butter, onions, bay, thyme, salt and pepper, and cook until light golden, 10-12 minutes. Remove bay leaf.
Arrange 1/3 potatoes in a casserole dish, season with salt and pepper and cover with half the onions and half of the meat. Repeat layers and top with remaining potatoes. Pour beer evenly over casserole and cover. Bake 2 1/2-3 hours until very tender.
Garnish with parsley and chopped pickles, and serve.