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