03After they have cooked, carefully remove the shortribs from the pot again. Stir in mustard, cream, and capers, then raise the heat and allow it to bubble up and gently boil for a good couple of minutes, or until it has thickened a bit. Taste and add more salt and pepper if needed. Return the shortribs to the sauce, put on the lid, and turn off the heat.
04To roast the mushrooms, preheat oven to 400 degrees. Arrange the mushrooms in a single layer on a baking sheet. Drizzle with olive oil and sprinkle with salt and pepper, then roast the mushrooms until they’re golden brown, about 15 to 20 minutes.
05Serve the shortribs on top of the mushrooms, then drizzle with extra cream sauce. Add a little rosemary sprig if you want to be fancy.