Heat olive oil in a large Dutch oven over medium heat until it shimmers.
Add the plant-based beef chunks in a single layer (working in batches if necessary) and brown for 3-4 minutes, turning occasionally to develop a nice crust on all sides. Remove and set aside.
In the same pot, add the diced onions and sauté for about 5 minutes until translucent and slightly golden.
Add minced garlic and cook for another minute until fragrant, being careful not to burn it.
Add carrots, celery, potatoes, and mushrooms to the pot. Cook for 5 minutes, stirring occasionally, until the vegetables begin to soften slightly.
Stir in tomato paste and cook for 2 minutes until it darkens slightly, which helps develop a deeper flavor.
Sprinkle flour over the vegetables and stir constantly for 1 minute to cook out the raw flour taste.
If using wine, add it now and scrape the bottom of the pot with a wooden spoon to release all the flavorful browned bits. Let the wine reduce by about half.
Gradually add vegetable broth while stirring to prevent lumps from forming.
Return the browned plant-based beef chunks to the pot, then add bay leaves, thyme, rosemary, and soy sauce.
In a small bowl, dissolve the miso paste in a few tablespoons of the hot broth, then stir this mixture back into the stew.
Bring the stew to a gentle boil, then reduce heat to low. Cover and simmer for 60-90 minutes, stirring occasionally, until vegetables are fork-tender and the sauce has thickened.
Add frozen peas during the last 5 minutes of cooking.
Remove bay leaves, taste, and adjust seasoning with salt and pepper as needed.