Well, tell us which pilgrim meals or restaurants along the Camino that serve dishes that consist of a heap of all kinds of sauteed vegetables in a big plate, which is ubiquitous in Thailand/Vietnam at few dollars? No, potatoes do not count.
I must admit I haven't had a pilgrim meal for a long time, in fact since my 1st camino in 2012, I never liked the main course nor the pudding! (I am not a big meat eater and I prefer cheese to sweet dishes). But I never suffered from lack of food or 'abysmal' food in Spain! Whichever region...
If you order a 'menu del dia' like the locals do, you'll have much more choice. As others above have mentioned, you can also get a big plate of vegetables a la plancha.
Also look at their 'carta': in season, they have wonderful dishes of small artichokes (alcachofas) cooked on a parrilla, broad beans (habas), leeks in vinagreta (puerros), always a wonderful tomato salad etc etc
It'll probably coast more than in Thailand or Vietnam (never been to Vietnam but used to go to Thailand frequently) but... it is certainly cheaper than my own country (France) and definitely much much cheaper than the country I live in (England).
Try it next time, I don't think you'll be disappointed
I am not just saying this to you of course but to any others who may have had problems with food on the Camino.
If on a budget, the alternative is to buy your own ingredients (they WILL be available) and share with other pilgrims. Unless it's a Sunday or a fiesta day lol (But I have had small shops opening especially for us pilgrims on the VdlP!)