My go to recipe is pasta, literally any kind and a sauce I make. In the sauce I'll start off by cooking a bunch of veggies (peppers, onions, tomatoes, and maybe zucchini) and then adding some jar of sauce to it. On the side I'll be cooking 2 chicken breasts. Divide it up evenly into a few tupperwares and throw in your cooler. Every single hotel you will stay at will have a fridge available to you. I'm a fan of bringing those small blue icepacks and i'll bring 4-5 with me in my cooler to keep it cold throughout the day. I'll also buy wraps or sandwiches premade at jewel for like 3.99 a piece that are great for a quick lunch. I'll buy those plastic containers at the supermarket full of a variety of fruit for a few dollars and bring 2 a trip. Big fan of bringing a few avocadoes. They're cheap and you can simply add salt/pepper and have a pretty filling and good snack. None of this is expensive, especially if you buy a huge pasta pack, big packet of like 20 chicken breasts from costco/sams. Veggies are like a dollar each, if that.