Pre-heat the oven to 325F.
Mix flour, paprika and the crushed mustard seeds in a large bowl. Coat the meat, a piece at a time and make sure the flour mixture covers the meat all over.
Use a large Dutch oven and brown the meat, a piece at a time on the stove. Once a piece is done, set it aside and let it rest.
Once done with browning all the meat, lower the heat a little, add a little bit more oil and the onions. Keep stirring them. Once translucent and you see some browning then remove the pot from the heat.
Pour in the marinade. Use a wooden spoon to scrape the brown bits that got stuck to the bottom. These brown bits of taste explosion will dissolve in the marinade and help thicken it up to a sauce.
Put the meat back in the pot and add 1-2 cups of water so the meat is touching the surface but not drowning. Place the pot in the oven, lid on, for 1.5h - 2h.
Add the cut up vegetables to the pot and put back in the oven for another 1h to 1.5h. The meat should be fork tender and the vegetables cooked just right.
Either cut up the meat in slices, or take a fork and break up the meat into smaller chunks. Place the meat in a serving dish and drizzle the thickended sauce on top.
Serve immediately with the sauce infused vegetables