Wash and peel the cucumbers, cut them in half lengthwise and remove the seeds. Cut the cucumbers into slices. Quarter peppers, clean, wash and cut into strips. Clean and halve mushrooms. Peel and chop onion.
Heat 1 tablespoon of oil in a frying pan. Fry the onion and minced meat for about 5 minutes, turning occasionally. Add 1 tablespoon of oil, heat up. Fry the mushrooms for about 3 minutes, remove.
Sauté the cucumber and peppers for 3-5 minutes. Add minced meat and mushrooms again, season with salt and pepper. Add vegetable stock, bring to the boil and cook everything for about 10 minutes at medium heat. Meanwhile cook the tagliatelle in plenty of bubbling salted water for about 10 minutes.
Stir the crème légère into the ragout. Bring to the boil again and season to taste with mustard, salt and pepper. Thicken with a little sauce thickener if necessary. Wash the chives, dab dry and cut into fine rolls.
Drain the pasta and arrange on plates with the stewed cucumber mince ragout. Sprinkle chives rolls over them.