Heat oil in a dutch oven or large soup pot over medium heat. Add dried thyme and rosemary then saute for 30 seconds. Add carrots, celery, and shallots, season with salt and pepper, and then saute until vegetables are browned and tender, 10 minutes. Add mushrooms then saute until tender, 7-10 more minutes. Add garlic then saute for 1 minute, or until very fragrant. Turn heat up to medium-high then add stew meat, red pepper flakes, lots of salt and pepper, and then saute until meat is browned, 8-10 minutes.
Whisk together melted butter and flour in a small dish then add to pot and stir to coat meat. Cook for 1 minutes then stream in beef broth. Turn heat up to high and bring stew to a boil then add bay leaves. Place a lid on top, turn heat down to medium-low, and then simmer for 2 hours, stirring occasionally.
Remove lid then simmer for another 1-1/2 hours, or until meat is tender and stew is thickened, stirring occasionally. If stew begins to thicken before meat is tender, place lid back on top. Taste and adjust salt and pepper if necessary then add frozen peas and cook for 2 minutes. Remove bay leaves then serve over mashed potatoes.
Working with a standard Dutch oven requires deliberate heat management to build deep savory foundations without scorching the bottom of the pot. When fat renders and vegetables release their moisture over medium-low flame, the surface reactions depend entirely on maintaining steady contact between the steel and the ingredients. Sautéing dried herbs like thyme and rosemary in oil for precisely 30 seconds releases fat-soluble aromatic compounds into the pan before the fresh aromatics go in. Maintaining control across these initial stages prevents the shallots and garlic from turning bitter before the heavier cuts of beef ever touch the heat.
Developing a rich body relies on a standard beurre manié approach where melted butter and flour are combined before hitting the pot. Whisking this paste directly into the browned meat coats each piece evenly so the starches hydrate without forming unpleasant lumps when the cold broth streams in. As the liquid reaches a boil and transitions to a covered simmer for two hours, collagen within the muscle fibers slowly melts into gelatin. This conversion is the sole physical mechanism responsible for transforming tough stew meat into tender morsels that yield effortlessly to a fork.
Evaporation controls final consistency during the uncovered phase where excess water escapes into the kitchen air over a 90-minute window. Removing the lid allows the starch-thickened stock to reduce properly, though watchful stirring remains necessary to prevent scorching as the liquid level drops. Adding frozen peas strictly in the final two minutes prevents them from turning khaki and mushy while preserving their bright green interior. Such precise timing separates a vibrant, velvety preparation from a dull, overcooked bowl.
Discarding the bay leaves before plating prevents diners from encountering bitter herbal fragments that failed to soften during the long cooking process. Serving the finished preparation over starchy bases like mashed potatoes provides structural contrast against the rich, reduced sauce. Recognizing the visual cue of a glossy, clinging gravy signals that the starches have gelatinized completely and the stew has reached its structural peak.