Wash the asparagus, cut off the woody ends. Cut the asparagus into small pieces. Wash, clean, quarter and seed the tomatoes. Cut flesh into small cubes. Wash thyme, shake dry, remove leaves, chop finely. Wash limes hot, grate dry. Finely grate the skin of 1 1/2 limes. Halve limes and squeeze 3 halves. Cut the remaining half into slices, set aside
Prepare the pasta in boiling salted water according to the instructions on the packet
Heat 2 tablespoons of butter in a saucepan. Steam the asparagus for 4-5 minutes while turning, season with salt and pepper and remove. Melt the remaining butter in hot frying fat. Sauté flour in it. Deglaze with cream and stock, simmer for 1-2 minutes. Stir in thyme, lime juice and zest, season with salt, pepper and sugar. Add asparagus, heat up
Take off some pasta water. Slice the parmesan. Pour the pasta into a sieve and drain. Put them back into the pot with the sauce and tomatoes, toss through, possibly dilute with some pasta water. Season pasta again, arrange with lime wedges and sprinkle with parmesan