Adjust oven rack to lower-middle position and heat oven to 325º
Sprinkle cut beef with salt and pepper.
Heat vegetable oil in large, heavy duty dutch oven on medium-high heat until shimmering
Add onions and 1/4 teaspoon of salt and pepper
Cook onions, stirring occasionally until well-browned. This should take about 8-10 minutes.
Add tomato paste and garlic.
Stir in and cook for one minute and fragrant.
Stir in flour and cook for another minute.
WHISK in the chicken broth, 3/4 cup of the beer, brown sugar and thyme.
Continue to stir, scrapping up all the brown bits off the bottom of the dutch oven.
Bring to a simmer and cook until slightly thickened, about 3 minutes
Stir in beef and return to a simmer.
Transfer to the oven and cook, uncovered for 90 minutes, stirring halfway through cooking.
Remove from oven and stir in potatoes and carrots.
Return to the oven and continue to cook until beef and vegetables are tender, about 1 hour, stirring halfway through cooking time.
Remove from oven and add remaining Guinness beer. Stir and add parsley.
Season with salt and pepper.
Serve with bread.