Roast a head of garlic dressed with olive oil in a 400 degree oven for 40 - 50 minutes.
Combine the chopped shallot with the tehina, lemon, black pepper, garlic butter, and a pinch of salt in a food processor and puree.
Be careful not to let the tehina overheat — add ice water, 1 tablespoon at a time, if the mixture seizes up.
Season with more salt if you like. Set the tehina sauce aside.
Heat the olive oil in a large skillet over medium heat.
Add the green beans and a pinch of salt and cook, stirring, until the beans start to soften, about 3 minutes.
Add the sliced shallot and the mushrooms to the skillet and continue cooking until the green beans are tender and lightly browned, about 10 minutes more.
Add the shallots and mushrooms and cook for 6 - 8 minutes softening the shallots and cooking the water out of the mushrooms.
Transfer to a bowl with a slotted spoon, discarding any excess oil. Set aside and keep warm.
To assemble, mix the tehina sauce with the green beans, shallots and mushrooms and spoon the mixture onto a serving platter.
Top with the tahina dressing.
Serve and enjoy!