To a large sauté pan over medium heat, add the oil and heat until it starts to slightly ripple. Add the mushrooms and cook until they start to brown, stirring. (see note) Add the shallots and sauté, until they begin to soften, 3-4 minutes. Add the garlic, rosemary, salt and pepper stir and cook for 2 minutes. Set aside to cool for 10 minutes.
Add the mushroom mix to a food processor along with the ricotta and blend until smooth, taste for seasoning.
Transfer to ramekins or container with a lid and refrigerate for 30 minutes until set.
Video
Notes
Will keep up to 1 week in a sealed container refrigerated.You must use a large enough pan so the mushrooms are not crowded and cook in a single layer. If not, they will release a lot of liquid and steam instead of brown.