If you don't have a wok just cook everything separately on a normal frying pan (on high) and take each item out onto a bowl.
Also, lightly salt everything too. It helps with even flavor and it helps some vegetables release some water (carrots for example).
If something is still too crunchy for your taste, add a little bit of water and let it evaporate, then repeat until it's cooked to your liking before taking it out.
After you're done with everything, make a mixture of whatever sauces you wanna use with water and cornstarch, thicken it in the same pan, then pour it over all the stuff you just cooked and mix.
Lot of work I know, but it's worth it.
Also, add the sesame oil in the end if you're using it for flavor. If you do it while cooking the flavor just goes away.