Use a jaccard steak tenderizing tool, or tenderize the steak yourself with a fork. Lay the meat out in front of you, pushing it flat with your hands or a meat mallet, and pull it gently apart with tines of the fork until the meat is slightly pulled apart and tender. Season with salt and pepper and dredge in flour. In a large oven-safe skillet over medium-high heat, add olive oil and brown steaks, in batches if necessary, on both sides, about 2 minutes per side. Set aside, keep warm.
Meanwhile, in a saucepan, reduce stock by half.
Season mushrooms with salt and pepper, to taste. Saute quartered mushrooms in the same pan as the meat, in the leftover olive oil, until very brown, about 5 minutes. Add butter, minced onion, carrot, thyme, and garlic. Cook until vegetables are caramelized, about 5 minutes, add balsamic vinegar and reduce for 1 to 2 minutes. Add broth, slide meat back into sauce, cover and bake until tender, about 1 hour.
Stack steaks with pea whipped potatoes and drizzle with balsamic/mushroom sauce.
Heat 1 tablespoon of the butter in a large saucepan over medium heat until the butter stops foaming and turns a light brown. Add the garlic and cook quickly until pale gold. Add remaining cream, season, to taste, with salt and pepper and bring to a boil.
Reduce the heat to low. Add the remaining butter by tablespoonfuls, stirring vigorously after each addition. In this way, the butter does not melt into a golden puddle. Instead, it forms an emulsion with the potatoes, creating a very smooth puree.
Fold the pea puree into the mashed potatoes and adjust seasoning, as necessary. Instead of salt, the puree can be seasoned with a little grated Parmesan, if desired.
Yield: 4 servings
Prep Time: 10 minutes
Cook Time: 20 minutes
Inactive Prep Time: 15 minutes
Ease of preparation: easy