Combine the bulgur and stock in a bowl and let soak until tender, approximately 45 minutes. After soaking, place the bulgur in a sieve and let the excess stock drain off. In a medium skillet, combine the olive oil and 1 tablespoon butter; sauté the mushrooms until will browned, about 10 minutes. In a large skillet, melt the remaining butter and sauté the shallot until tender but not browned, about 5 minutes. Add the bulgur and thyme and heat thoroughly. Add the mushrooms and season to taste. Serve hot.