Sirloin steaks with Marinated Mushrooms and Mascarpone Mash

I classify this as a mid week 1 hour recipe, packed with nutrients and good flavour. Recipe is for 4 persons

700g sirloin steaks cut into wide strips
1 teaspoon pink pepper corns
1/2 tsp salt
2 cloves garlic
2 tsp cornflour
1 tablespoon olive oil

For Marinated Mushroom filledTomatoes

4 large round tomatoes
1 kilo mushrooms
1 litre Water
250ml white wine vinegar
1 tablespoon sugar
1 lemon                                                                                                Mascarpone Mash
1 bay leaf                                                                                             1 Kilo Potatoes
3 tablespoons olive oil                                                                          100g Mascarpone cheese
1 teaspoon english mustard                                                                   Salt
1 teaspoon mustard seeds                                                                     3 tablespoon Milk
salt & pepper                                                                                       (boil Potatoes until soft, mash and
1 tablespoon vinegar extra                                                                     add Mascarpone and Milk. Season
1 teaspoon honey                                                                                  with salt to taste)
1 tablespoon chopped fresh parsely

Crush pepper corns with garlic and salt, add to a bowl. Add cornflour mix well add beef and drizzle with olive oil. Using your hands mix thoroughly, leave to marinade for 15 minutes.  Meanwhile prepare the mushrooms by bringing to boil in a medium pan Water, Vinegar, Juice of half a lemon, salt sugar and bay leaf.  Slice mushrooms and blanch in boiling vinegar water for 2 minutes. Lift with slotted spoon and transfer to plastic colander and leave to drain. With the heat still on, put tomatoes in the same liquid for 30seconds. Lift tomatoes and turn off heat.  Peel tomatoes cut in two and scoop out the seeds.  Make the mushroom dressing by mixing the remaining half lemon juice, mustard, mustard seeds, salt & peppe,r honey, extra vinegar to olive oil. Mix with a small whisk until well combined ( it should emulsify). Transfer mushrooms to clean glass bowl add the marinade and chopped parsely and mix well. 

Right before serving, heat a large non stick pan and dry fry the sirloin strips.  Season well tomato with salt and pepper, arrange on a plate and fill with Marinated mushrooms.  Arrange beef and mash. Drizzle with some of the mushroom marinade on top.