Here are a couple of my favorite lunch ideas for hot days that are easy to make ahead and don't require reheating once you're in the office.
This cheese-free frittata is loaded with vegetables and is tasty served cold:
Note: Bacon fat or butter make for a much cleaner release from the pan, and both fats add wonderful flavor to this dish, but if you are particularly averse to them both, refined coconut oil or olive oil will work—you’ll just have a messier cleanup and a less neat serving appearance.
freshly ground black pepper
1 1/2 tablespoons butter or bacon fat
1 spring onion, diced
1/2-1 cup cut-up asparagus spears
1/2 medium bunch lacinato kale, cut into ribbons (about 2 cups)
Heat broiler. Beat eggs lightly with several generous pinches of sea salt and black pepper. Heat 1 tablespoon fat in a medium skillet over medium heat; add onion and a pinch of salt and cook until soft, about five minutes. Add asparagus and cook about 2 more minutes. Add kale and a splash of water and cook until kale stems are almost tender and additional water has cooked off. Add remaining fat and allow it to melt. Turn heat down to low, add eggs, and stir occasionally as if making scrambled eggs. When eggs are half cooked, place under broiler for about 2 minutes, or until cooked through. Immediately remove frittata to place and serve, or cut into slices to cool.
My lighter version of tuna salad (with an olive oil/vinegar dressing - no mayo required) is great with lettuce leaves or crackers: one can of olive-oil packed tuna, drained; 1/2 red bell pepper, diced; zest and juice of 1/2 lemon; about a teaspoon of capers and a few splashes of brine; a small handful of rough-chopped olives; a pinch of cayenne and plenty of freshly-ground black pepper; a glug or two of extra-virgin olive oil. Mix everything together and add sea salt and vinegar to taste.