Cover a sheet pan with foil then place a cooling rack on top. Lay bacon strips on top of cooling rack then place the baking sheet into a cold oven and preheat to 375 degrees. Let the bacon bake as the oven warms up, then continue baking until crispy. Chop when cool enough to handle then set aside.
Meanwhile, fill a medium-sized bowl with ice and water then set aside. Add eggs to a medium-sized saucepan then cover with water 1" above the tops. Bring water to a boil then place a lid on top and remove pan from heat. Let sit for 11 minutes then remove the lid and scoop eggs into the bowl of ice water and let cool. Peel eggs then chop and add to a large bowl.
To the chopped eggs add the mustard, paprika, mayonnaise, salt, pepper, and lemon juice to taste then stir to combine. Add green onions then stir to combine.
Scoop 1/3 of the egg salad into the bottom of each mason jar then top with 1/3 of the tomatoes, 1/3 of the bacon, and then fill the to the top with arugula/greens. Screw on lids then store in the refrigerator for up to 4 days.