Wash the thyme, dab dry and remove the leaves. Wash lemon hot, rub dry and tear off zest. Finely chop lemon peel and thyme. Peel and finely chop 1 clove of garlic. Mix lemon zest, thyme, garlic and 75 ml olive oil. Dab meat dry and mix with the spice oil, marinate for about 1 hour, turning occasionally
Remove the meat from the marinade and dab a little dry. Heat a large pan. Fry the meat for about 5 minutes, turning it over. Season the meat with salt and pepper, place in a greased casserole dish and cook in a preheated oven (electric cooker: 100 °C/ convection oven: 75 °C/ gas: unsuitable) for 25-30 minutes until medium rare
Meanwhile peel the shallots and 1 clove of garlic and dice them finely. Heat 2 tablespoons of oil in a frying pan and sauté the onion and garlic. Add tomato paste, sweat briefly, add chunky tomatoes and 150 ml water. Bring to the boil, add stock and simmer over a mild heat for 10-15 minutes. Season to taste with salt, pepper, balsamic vinegar and sugar
Halve the lemon, squeeze the juice. Wash the asparagus, cut off the woody ends. Boil up plenty of salted water with 3-4 tbsp lemon juice and sugar. Cook the asparagus for 6-8 minutes, remove. Remove beef fillet from the oven and let it rest for about 3 minutes. Arrange meat with tomato sauce and asparagus on plates. Garnish with thyme and grated lemon peel
Waiting time approx. 1 hour