She taught us how to make a spectacular, yet simple, all-purpose tomato sauce: just olive oil, garlic, tomatoes, salt, and a few red-pepper flakes…simmered and blended to smooth perfection. But she’s wintering in Australia, so instead, her mother Laura invited us into her home kitchen to cook — and eat — an extravagant Tuscan lunch. One thing I’ve learned from cooking in a Tuscan kitchen: Americans are afraid to use nearly as much salt and olive oil as Italians do. Then came the pasta course: handmade ravioli stuffed with nettle greens and ricotta cheese. Into the pot went water, abundant olive oil, a few cloves of garlic, pepper flakes, and a little sachet of fresh sage and rosemary.