Preheat oven to 195℃/383℉. (I see many casserole recipes recommend lower temperatures. This works for me for this recipe.)
In the baking dish, toss the meat chunks in flour, salt and pepper, making sure it is well covered.
Add vegetables to the dish and toss them with any remaining flour. Add sugar, sauces, mustard, stock. Stir to mix everything. Season with salt and pepper.
Cover baking dish tightly with a lid or foil. Bake for 2½ hours. Turn at halfway point to ensure meat is still covered by liquid and not sticking to foil. Often it looks too liquidy at this point. Don't worry, it will thicken.
Season to taste. Top with fresh herbs if you like. Serve with potatoes, rice, pasta, or bread.