In a large bowl, combine all meatball ingredients until well combined. Do not overmix, or the meatballs can become hard. Roll into 20-25 equal-sized balls.

Heat 2 tablespoon olive oil in a large dutch oven or braiser over medium-high heat. Brown meatballs on all sides, working in batches if necessary. Remove to a plate.

Reduce heat to medium. Add remaining tablespoon of olive oil if needed. Add onion, carrots, celery, and mushrooms. Sauté until they are beginning to soften, about 5 minutes. Add garlic and flour, mix well, and cook 1 minute.

Gradually add wine, stirring to deglaze the pan, scraping up all the browned bits on the bottom of the pan. Add in tomato paste, and combine well. Simmer and reduce for 5 minutes.

Add beef broth, thyme, rosemary, bay leaf, and browned meatballs. Mix well. Increase heat to medium-high, bring to a simmer, then reduce heat back down to medium. Simmer for 15-20 minutes.

Add in potatoes. Cook for 25 minutes.

Add green beans and peas. Cook for about 5 additional minutes, or until potatoes and green beans are cooked to your liking. Taste and adjust for salt.

Remove from heat. Allow to rest for 5-10 minutes, then serve.

Form and brown the meatballs as described in steps 1 and 2 above.

Sauté onion, celery, carrots, and mushrooms in the same pan, then transfer to the slow cooker.

Transfer the vegetable mixture to the crock pot, along with all remaining stew ingredients except corn starch.

Mix well, then place the meatballs into the mixture.

Cover and cook on low for 5-6 hours, or high for 2-3 hours.

When stew has finished cooking, combine corn starch with ¼ cup cold water. Mix well, then slowly stir into the stew. Allow to cook 5-10 minutes longer, uncovered, to allow the stew to thicken.

Form meatballs as described in step 1 above.

Set the Instant Pot to Saute mode. Add 2 tablespoon oil, then once hot add meatballs (working in batches) and brown on all sides. Remove to a plate.

Add additional oil if needed, then sauté onion, celery, carrots, and mushrooms until they begin to soften. Add flour and garlic, mix well and cook for one minute. Turn off the Instant Pot.

Add in remaining ingredients. Stir well, making sure to scrape any browned bits off the bottom. Place meatballs into the mixture.

Add the lid, seal, and cook on high pressure for 30 minutes, followed by a natural pressure release.

Combine corn starch with ¼ cup cold water. Mix well, then slowly stir into the stew. Allow to cook on Saute mode for 5-10 minutes to allow the stew to thicken.