Put the fava beans in a pan, cover with water, and bring to a boil. Lower the heat and simmer for 5 to 10 minutes (depending on the beans’ age and size) until tender, then drain. Set aside to coll, then slip the beans out of their skins.
Put the peeled fava beans in a food processor or blender with the garlic, 3 tablespoons of oil, a good squeeze of lemon juice, and some salt and pepper. Process to a thick, slightly coarse purée, adding more oil if it seems too thick and dry.
When you’re happy with the texture, transfer the purée to a bowl. Taste and adjust the seasoning with more salt, pepper, and lemon juice as needed.