Cook egg noodles in large pot of boiling salted water until tender, stirring occasionally, according to package directions. While noodles cook, place frozen green peas in the bottom of the strainer.
Drain noodles, pouring the hot water right over the green peas, and reserving ¾ cup pasta cooking liquid. Transfer noodles and peas to large bowl. Add the tuna and all the juices from the can of tuna to the pasta, breaking up the tuna into small pieces. Set aside.
In the same pot that you cooked the noodles in, melt the butter over medium-high heat. Once the butter is melted, slowly add the flour, a little at a time, stirring constantly to keep smooth. Reduce the heat to low.
Slowly pour in the milk, stirring as you add. Simmer over low heat to thicken, about 5-10 minutes. Stir often.
Stir in the spices (thyme through pepper), to the sauce mixture, and remove from heat. Stir in the cheese until the cheese is melted. Stir sauce mixture into pasta and tuna mixture. If mixture is too thick, stir in some of the reserved pasta cooking water, about 1-2 tablespoons at a time until desired consistency is reached. Taste for salt and pepper.