Peel carrots and cut into pieces. (about 1 cm thick)
Halve the leek lengthways and cut into strips (also 1 cm wide). Wash well and drain.
Wash the celeriac, remove the threads and cut into 1 cm pieces.
Peel onion and garlic and cut into cubes.
Heat vegetable oil in a Dutch oven over medium-high heat.
Add the onions and simmer until they start to colour. Remaining vegetables incl. Add garlic to saucepan and simmer, stirring constantly, until caramelized, about 5 to 6 minutes.
Add the vegan meat substitute, stir and cook for a few minutes. I fry the vegan alternative briefly and vigorously in an extra pan. (but this is optional)
Add the tomato paste and stir to combine all the ingredients. Let the tomato paste fry a little on the bottom of the pot. This not only ensures a smoky taste later, but also a perfect color of our Irish stew.
Pour in the Guinness and fill up with the vegetable stock until everything is just covered. Bring to the boil and simmer gently for about 40 to 50 minutes. Stir occasionally.
Season with salt, pepper and possibly sugar.
Thicken with cornstarch mixed with cold water to desired consistency.
Enjoy with fresh bread or mashed potatoes!