In a 5- to 6-quart covered pan over high heat, bring 2 1/2 to 3 quarts water to a boil.
Peel and thinly slice onion. Rinse, stem, and seed peppers; slice lengthwise into 1/4-inch-wide strips. Rinse and core tomatoes; cut each lengthwise into 6 wedges.
In a 12-inch nonstick frying pan or a 5- to 6-quart nonstick pan over high heat, stir onion and bell peppers in oil until limp, about 5 minutes. Add paprika and caraway seed; stir. Add tomatoes and broth; stir until boiling.
Add noodles to boiling water and cook until barely tender to bite, about 5 minutes; drain.
Meanwhile, discard any solidified fat from pot roast and sauce. Scrape sauce from meat and mix with vegetables in frying pan. Cut beef across the grain into 1/4-inch-thick slices. Put slices in pan; cover, reduce heat, and simmer until beef is hot, 5 to 6 minutes.
Pour hot noodles onto a rimmed platter. With a wide, slotted spatula, lift beef from pan and mound on noodles. Spoon vegetables and sauce around and over beef. Sprinkle with parsley.