How to reshape latitude, longitude and data of not regularly-spaced vectors into 2-D matrix to plot a pcolorm?

I have latitude, longitude and data vectors of size 7631 that are not equally spaced.

I want to plot a pcolorm of the data at the given latitude and longitude.

Since my data is not regularly-spaced I have a hard time being able to do a pcolorm.

I thought it would work with latitude, longitude and data as vectors but it does not work properly.

I am converting data from a x-y grid to a lat-lon grid. I want to reproduce the figure on the x-y grid below on the geo-referenced map.

% Load latitude, longitude & data
load('lat_lon_data.mat');

figure(1);
ncpolarm('lat',66); hold on;
%pcolorm(latitude,longitude,data); %NOT WORKING

Figure on my original x-y grid that I want to convert on a georeferenced map:

Georeferrenced map on which I want to do a pcolorm of my data.

Thank you